Every gaming term clearly defined. Whether you are wondering what an idle game is, what permadeath means, or how a Metroidvania differs from a Souls-like, this glossary has plain-English answers.
41 terms across browser game tech, genres, gameplay mechanics, and gamer slang. Every definition is written to be cited directly — feel free to link or quote.
A side-scrolling action game where a character walks through levels defeating waves of enemies in melee combat.
Beat 'em ups (also written beat-em-up or brawler) drop you into a city street, dojo, or alley and send waves of enemies at you. Combat is close-range, punch-kick-throw style. Double Dragon and Streets of Rage are classic examples; modern browser versions keep the formula simple and approachable.
A climactic battle against a single, much tougher enemy that caps a level or story chapter.
A boss fight pits the player against an oversized or unique enemy with distinct attack patterns and high HP. Bosses usually have multiple phases — as you damage them, their behavior changes. Winning a boss fight often unlocks the next area or rewards special loot.
Any video game that runs entirely inside a web browser without installation.
A browser game loads and runs in a standard web browser (Chrome, Safari, Firefox, Edge). There is no install step, no app store, and no update process — opening the page launches the game. Modern browser games use HTML5 or WebGL under the hood and often work on any device with a browser.
A top-down shooter where enemies fill the screen with dense, intricate bullet patterns you must weave through.
Bullet hell games (sometimes called "danmaku" in Japanese) are an extreme subgenre of shoot-em-ups where the screen is literally filled with bullets. The challenge is pattern recognition and precise movement through tiny safe zones. The player ship usually has a small hitbox to make the seemingly impossible patterns survivable.
A game designed for short sessions, simple controls, and easy learning — suitable for non-dedicated players.
Casual games target players who want quick entertainment without committing to long sessions or learning complex systems. They feature simple controls (often one-tap or mouse-only), short play sessions, and forgiving difficulty. Most browser and mobile games fall into the casual category.
A save point reached during gameplay, so that dying does not send you back to the start.
A checkpoint is an automatic save that happens when you reach a specific location in a level. If you die after passing the checkpoint, the game respawns you there instead of the beginning. Checkpoints keep progress without requiring manual saves — useful on mobile and in browser games.
The waiting period after using an ability before you can use it again.
A cooldown is a timer that prevents an ability from being used again immediately. After firing a powerful spell or using a special move, the ability is disabled for a few seconds (or longer). Cooldowns prevent players from spamming overpowered actions and add timing as a strategic layer.
A game where the character runs automatically forever and the player just reacts to obstacles.
Endless runners feature auto-scrolling movement — your character never stops running. The player only controls jumping, sliding, and sometimes lane switching to avoid obstacles. The game never ends until you crash. Temple Run and Subway Surfers made the genre famous on mobile.
A shooter game viewed from the character’s own perspective, through their eyes.
FPS stands for First-Person Shooter. The camera is positioned at the character's head, so you see the world as they would — with their weapon visible in the lower part of the screen. Doom (1993) defined the modern FPS; browser versions of Counter-Strike and similar games keep the genre alive in HTML5.
The number of images displayed per second during gameplay, measured in frames per second.
Frame rate (FPS, not to be confused with first-person shooter) measures how smoothly a game displays motion. Most games target 30 FPS or 60 FPS. Higher frame rates feel smoother and more responsive but require more computing power. Browser games typically run at 60 FPS on modern devices.
A game that costs nothing to download and play, usually monetizing through cosmetics, ads, or optional purchases.
F2P games have no upfront cost. They make money through optional microtransactions for cosmetics, convenience items, or character unlocks, or by showing ads. True F2P games let you enjoy the full experience for free. FastPlayGames takes the free-to-play model further — no accounts, no purchases, no ads blocking gameplay.
A numeric measure of how much damage a character can take before dying.
HP stands for Hit Points (sometimes Health Points). It is typically displayed as a number or a health bar. When it drops to zero, the character dies. Damage from enemies reduces HP; healing items or spells restore it. The term originated in tabletop RPGs and carried over into video games.
A game built with HTML, CSS, and JavaScript that runs directly in a web browser without any plugin.
HTML5 games use the open web platform — HTML5 Canvas, WebGL, and JavaScript — to render graphics and handle gameplay. They run in any modern browser on desktop, tablet, or phone, with no installer, no app store, and no third-party plugin like Flash. HTML5 is the standard that replaced Adobe Flash for browser gaming after 2020.
Examples on FastPlayGames: 2048, Doodle Jump, Block Blast
A game where progress continues automatically even when you are not actively playing.
Also called incremental games, idle games reward players for minimal interaction. You set up production, click or tap occasionally, and watch resources grow. Progress continues between sessions, so you come back to see what your character or factory accomplished while you were away. Cookie Clicker and Adventure Capitalist popularized the genre.
A game built around numbers that gradually grow larger as you unlock multipliers and upgrades.
Incremental games (closely related to idle games) focus on exponential number growth. You start with small gains per click, unlock multipliers, then unlock ways to multiply the multipliers. The gameplay loop is about planning the order of upgrades to maximize growth. Prestige systems let you reset for long-term bonuses.
A free browser-based multiplayer game with a .io domain, typically featuring quick matches and competitive gameplay.
IO games (named after the .io top-level domain used by the earliest titles like Agar.io and Slither.io) are multiplayer browser games designed for short, competitive sessions. They usually feature simple controls, instant-action gameplay, and real-time matches against other players. No download or account is required — you join a public lobby and play.
A delay between player input and on-screen response, usually caused by network or hardware bottlenecks.
Lag is any noticeable delay in a game. Network lag (high ping) affects multiplayer — you press a button and the server responds late. Frame rate lag (low FPS) makes the image stutter. Input lag is the delay between pressing a button and seeing the effect. All three can ruin competitive play.
A puzzle game where you swap or align three or more identical items to clear them from a grid.
Match-3 puzzles present a grid of colored tiles or gems. Swap two adjacent tiles to form a row or column of three or more matching items, which then disappear, with new tiles falling to fill the gap. Bejeweled popularized the genre; Candy Crush Saga and Block Blast are modern descendants.
A 2D action-adventure game built around exploring an interconnected map and unlocking new areas via acquired abilities.
Named after the Metroid and Castlevania series, a Metroidvania game features a single large map you explore non-linearly. Early on, certain passages are blocked — you must find abilities (double jump, wall climb, bomb) that let you backtrack and access new areas. The joy is the gradual unlocking of the world.
A Massively Multiplayer Online game, where thousands of players share the same persistent world.
MMO stands for Massively Multiplayer Online. Unlike regular multiplayer games with small lobbies, MMOs host thousands of players simultaneously in a shared world that persists whether you are logged in or not. Most MMOs require accounts; browser-based MMOs are rarer but exist.
A Massively Multiplayer Online Role-Playing Game — an MMO with RPG elements like leveling, quests, and character classes.
MMORPGs combine the massive scale of MMOs with role-playing mechanics. Players create characters, pick classes, complete quests, and level up while interacting with other players. World of Warcraft is the most famous example; several browser MMORPGs exist as well.
Any character in a game controlled by the computer, not by a human player.
NPC stands for Non-Player Character. Shopkeepers, quest givers, townsfolk, enemies, and bosses are all NPCs. In multiplayer games, NPCs fill roles that no real player is playing. The term dates back to tabletop Dungeons & Dragons.
A game design where the player is free to explore a large, continuous world instead of being funneled through linear levels.
Open-world games give the player freedom to travel across a large map in any order. Quests can be tackled in whatever sequence, and often there are side activities, collectibles, and hidden areas to find. Skyrim and Grand Theft Auto V are mainstream examples; smaller browser open-world games exist as well.
A monetization model where spending money gives players significant in-game advantages over non-paying players.
Pay-to-win describes games where money can buy direct gameplay advantages — stronger weapons, faster progression, exclusive characters — over players who don't pay. The term is usually pejorative, since P2W mechanics can make competitive play unbalanced. F2P games without P2W mechanics typically sell only cosmetics.
A rule where character death is permanent — you cannot reload a save or retry the level.
Permadeath (short for "permanent death") means dying in-game ends that character or run forever. Many roguelikes and hardcore modes in RPGs use permadeath to add weight to every decision. In games without permadeath, dying just loads the last save point.
A game centered on jumping between platforms, timing leaps, and avoiding hazards.
Platformers (also called platform games) are defined by jumping mechanics. Levels are made of platforms arranged at different heights, and the player controls a character who must jump across gaps, land on enemies, or avoid falling into pits. Super Mario Bros. defined the 2D platformer; modern browser versions range from retro pixel art to 3D isometric designs.
Game content created by algorithms at runtime instead of being hand-designed in advance.
Procedurally generated content (PCG) is made by code, not by level designers. Many roguelikes use PCG for dungeons so each run is different. Minecraft generates entire worlds procedurally. PCG increases replayability because you cannot memorize a fixed layout, but it also means content varies in quality compared to hand-crafted design.
A browser game that can be installed like a native app and runs offline using service workers.
A Progressive Web App game uses web standards (service workers, manifests) to behave like a native mobile app. After visiting the site once, you can "install" it to your home screen. It will launch in its own window, work offline, and receive updates automatically. PWA games avoid the app stores entirely.
A deliberately difficult game designed to frustrate the player, often with unfair mechanics and punishing setbacks.
Rage games (or "kaizo" games) are built to make players lose their temper. The difficulty is usually obscene, checkpoints are sparse or nonexistent, and dying sends you far back. Getting Over It with Bennett Foddy and I Wanna Be the Guy are famous examples.
A game featuring procedurally generated levels, permanent death on failure, and run-based progression.
Roguelikes borrow their name from the 1980 game Rogue. Each playthrough generates new levels randomly, and if your character dies, you start over from the beginning. The genre rewards mastery and adaptation — you might unlock permanent bonuses between runs (a subgenre called roguelite), but each attempt is unique.
A game where players take on a character and grow them over time through quests, combat, and choices.
RPG stands for Role-Playing Game. Players control a character (or party of characters) who earn experience points, level up, unlock new abilities, and progress through a story. RPGs emphasize long-term character growth and narrative, unlike action games where skill dominates.
A strategy game where actions happen continuously in real time rather than in turns.
RTS stands for Real-Time Strategy. Unlike turn-based strategy games, in an RTS both sides give orders simultaneously and the action never pauses. Classic examples include StarCraft and Age of Empires. RTS games demand multitasking: managing economy, army, and scouting at once.
A browser security feature that isolates an iframe from the parent page, preventing it from accessing cookies, data, or controls.
An iframe sandbox is a browser-enforced boundary. When a game loads inside a sandboxed iframe, it cannot read cookies, access the parent page’s DOM, or make cross-site requests. This keeps users safe: even a malicious game cannot steal data or modify the host site. FastPlayGames sandboxes every embedded game.
A game that gives the player tools and freedom to create, build, or experiment rather than follow a fixed goal.
Sandbox games prioritize player creativity over fixed objectives. Minecraft is the most famous example — it gives you blocks and lets you build whatever you imagine, with optional survival mechanics on the side. Other sandbox games let players drive physics, mix chemicals, or design cities.
A shooter game where the player moves a ship or character through levels firing at swarms of enemies.
Shoot 'em ups (or shmups) are all about shooting. Most are top-down or side-scrolling, with the player controlling a spaceship or plane that fires continuously at incoming enemies. Space Invaders and Galaga are the ancestors of the genre.
A difficult action RPG inspired by FromSoftware’s Dark Souls series, featuring brutal combat and steep learning curves.
Souls-likes borrow the design principles of Dark Souls: deliberate combat, stamina management, punishing difficulty, minimal hand-holding, and death as a teaching mechanic. Enemies are deadly but predictable — the challenge is learning their patterns. Most souls-likes have "losing progress on death" mechanics.
The act of a character, enemy, or item appearing in the game world.
"Spawn" describes when something appears in-game. Enemies spawn at set locations or randomly, items spawn in chests, and players respawn at checkpoints after dying. The "spawn point" is the location where you first appear or reappear.
The practice of completing a game as fast as possible, often using optimized routes and glitches.
Speedruns are attempts to finish a game in the shortest possible time. Runners memorize optimal paths, exploit known glitches, and practice frame-perfect tricks. There are usually different categories: "any%" allows anything, "100%" requires full completion, and "glitchless" bans exploits. Speedrun.com tracks world records.
A strategy game where you place defensive towers along a path to stop waves of enemies.
Tower defense games give you a fixed map with a path enemies walk along. Between waves, you spend resources to build and upgrade towers that automatically attack enemies in range. The strategic depth comes from tower placement, upgrade order, and counters for different enemy types.
A browser game that plays on networks where game sites or app stores are typically restricted, like schools or workplaces.
Unblocked games are standard browser games hosted on domains and CDNs that are not filtered by common school and workplace network blocklists. They do not require a VPN, a proxy, or an account. Since they run in a sandboxed iframe, they cannot install software or modify the network.
A reward currency earned by defeating enemies or completing quests, used to level up.
XP stands for Experience Points. Most RPGs award XP for killing enemies, finishing quests, or reaching milestones. Once you accumulate enough XP, you level up — gaining stat boosts, new abilities, or higher max HP. The more XP required per level, the slower the progression curve.