2D Platform Games

Getting Started With 2D Platform Games

Most people come into this genre thinking it is just jumping on platforms. It is not. The real work happens in the gaps between pixels, and the difference between a game that feels good and one that feels like garbage usually comes down to how you handle frame-by-frame movement, hitbox scaling, and input buffering. I spent three years building platformers before I stopped shipping broken prototypes. A basic platformer loop reads inputs, applies acceleration or deceleration, checks collisions against tilemaps or polygonal geometry, and renders at a fixed timestep. The fixed timestep is the part everyone messes up. If you tie physics to your render framerate, the character will move faster on a 144hz monitor than on a 60hz one, which breaks level design expectations across the board. Lock your physics updates to something like 60 updates per second and let the renderer interpolate between frames. You can run the renderer at whatever refresh rate the display supports while the physics stays deterministic. Collision detection is the next place things fall apart. AABB versus AABB is fine for simple cases, but you need to handle wall sliding, ceiling bumps, and one-way platforms separately or the player gets stuck in corners. My approach was to run collision resolution along one axis at a time. Move on X, resolve X collisions, then move on Y, resolve Y collisions. This eliminates diagonal tunneling through thin walls and makes corner catching rare enough that you do not need to overcomplicate it. When you do need precise hitboxes, use separate collision shapes for the character versus the player perception box. The math hitbox can be smaller than the visual sprite without anyone noticing, which reduces false collisions against tiles the character should logically pass near.

I learned this the hard way when I shipped a test build where the player could clip through a two-tile gap if they pressed jump and move diagonally at the exact same frame. The input was being read before the previous frame's collision response finished applying, which meant the movement vector was calculated from a position that had not yet settled. The fix was straightforward: I moved input buffering to occur at the start of the frame, before any physics calculations ran, so every movement decision used a fully resolved position from the prior tick. That solved the clipping and also made the controls feel tighter because the input was no longer fighting against a half-updated state.

Core Systems You Need to Build

Movement and acceleration curves. Most beginners just set a flat speed value. Real platformers use acceleration and deceleration rates, which gives the character weight. A typical setup looks like an acceleration of around 1500 pixels per second squared for moving forward and a deceleration of roughly 2000 when you let go of the input. Higher deceleration than acceleration makes the controls feel snappy. If you want a slippery or floaty feel, you lower both numbers and adjust the jump force accordingly. Jump mechanics. Variable jump height is standard. Holding the jump button longer produces a higher jump, but releasing early cuts the upward velocity. You do this by checking whether the jump input is still active each frame and applying a reduced vertical gravity when it is not. The typical jump force lands somewhere between 600 and 900 pixels per second depending on your gravity scale. Gravity itself usually sits around 2000 to 3000 pixels per second squared. These numbers sound arbitrary until you playtest them against your actual level heights. One-way platforms. These are non-negotiable for any serious platformer. The rule is simple: allow the player to pass upward through the platform, but block downward movement when the player is above it. The edge case is when the player is falling and their feet are exactly aligned with the platform surface on the frame before contact. Without a small grace buffer, the player can fall through. I use a margin of about 2 pixels below the platform surface where downward collision is still enforced even on a one-way tile. It is tiny but it prevents the frustration of missing a landing by a single frame.

Wall sliding and wall jumping. These add depth without adding complexity to the engine. Wall slide triggers when the player is touching a vertical surface and pressing toward it while in the air. Reduce gravity by about 60 to 70 percent during the slide. Wall jump is just a standard jump with a strong horizontal impulse away from the wall. The common pitfall here is making the wall slide too slow, which makes players feel like they are stuck. If the slide speed is under 100 pixels per second, most people will find it annoying rather than useful.

Level Design Considerations

The grid matters. Tile-based design is still the most practical approach for 2D platformers because it gives you instant visual feedback while placing objects. A 16x16 or 32x32 tile size is standard, but what actually matters is that your character dimensions are multiples of your tile size or at least divide cleanly into the collision grid. A character that is 24 pixels wide on a 32-pixel tile grid creates awkward partial overlaps that make both level editing and collision math harder than they need to be. Jump arc planning is the skill that separates competent level designers from people who just place gaps randomly. Every gap should be jumpable with a full hold and not jumpable with a short tap, or vice versa if you are going for a more forgiving game. Test each gap with the minimum jump, medium hold, and full hold before you lock it in. If a gap is possible with any amount of jump input, it is too easy. If it is impossible even with full hold, it is too hard unless you have a visible checkpoint or safety net below it.

Tools and Where to Find 2D Platform Games

If you are building from scratch, Godot and Unity are the two engines most people use for this genre. Godot handles 2D natively and its physics setup is lighter, which matters when you are debugging collision edge cases at 3 AM. Unity works fine too but you will spend more time configuring the 2D physics materials and colliders. For rapid prototyping, GameMaker still ships some of the cleanest built-in platformer templates, though the language syntax takes a day to get used to if you are coming from Cor GDScript. If you are looking for existing 2D Platform Games to study rather than build, itch.io has a large selection of free and paid titles across the metroidvania and precision platformer categories. Steam also has a solid filter for 2D platformers if you want to analyze commercially released games. Playing these with a focus on how they handle speed, checkpoint placement, and death penalties tells you more about design than any tutorial will. I spent more time modding old Flash platformers in browser archives than I did reading documentation when I was trying to understand why certain games felt smooth.

Common Pitfalls and What to Do Instead

Over-relying on invisible helper platforms. Players will notice when a platform appears just to save them from a death. It breaks immersion immediately. If a section requires a safety net, either make it visible from the start so the player knows it is there, or use a checkpoint system that does not require phantom platforms. Some games use a rewind mechanic instead, which handles deaths differently and removes the need for hidden platforms entirely. Butrewind mechanics introduce their own debugging headaches around state rollback, so weigh that cost carefully. Ignoring camera behavior. The camera is not just a framing tool. A poorly tuned camera can make a perfectly fair platformer feel unfair by cutting off visual information the player needs to judge a jump. Keep the camera ahead of the player by a small margin, but do not let it teleport. Smooth interpolation on camera movement prevents disorientation. A lag of 0.1 to 0.2 seconds on the camera follow is usually the sweet spot. Anything slower and players feel like they are watching the action through molasses. Anything faster and the camera becomes distracting during tight platforming sections. No-look death gaps. These are sections where the player dies without seeing the cause. They happen when a hazard or enemy is offscreen or when the camera cuts off a falling section. If the player cannot see why they died, they will assume the game is broken and stop trusting your design. Always give the player enough information to understand a failure state. Even a brief visual or audio cue before death helps. A quick flash or impact sound tied to the hazard origin point is enough for most players to register what killed them.

Performance Notes You Should Not Skip

Even 2D games can choke if you are not careful about how you handle rendering. Batching sprites by texture atlas reduces draw calls significantly. If you are using individual sprites for every tile and character animation frame without atlasing, you will see frame drops on lower-end hardware within the first ten minutes of gameplay. A single atlas with all your tile and character textures keeps draw calls low and makes level streaming smoother. This is especially relevant if you plan to support mobile or switch-class hardware. Object pooling for projectiles, enemies, and particle effects is another quick win. Instantiating and destroying objects every frame during a dense enemy encounter creates garbage collection spikes that manifest as micro-stutters. Pool ten to twenty of each object type and reuse them. The pool size depends on your worst-case scenario for how many active entities exist simultaneously. Five enemy types at four instances each means a pool of at least twenty for enemies alone, plus whatever projectiles and particles your combat system generates.

Final Thoughts on Shipability

The genre is saturated. There are thousands of platformers released every year and most of them fail because the core movement feels slightly off. Before you add bosses, lore, or a story, ship a single level that is three minutes long with ten distinct obstacles and get strangers to play it without guidance. If they can complete it on their first try, the movement is too easy. If they cannot complete it after three attempts, something is unclear or unfairly difficult. Adjust until the death-to-success ratio lands somewhere between two and five attempts for a well-designed level. That is the range where players feel challenged but not punished. The tools and techniques described here are well established. Nothing about 2D platformer development is particularly new or secret. What makes a game stand out is execution, iteration, and willingness to throw away systems that feel good on paper but fail in practice. I have deleted entire movement implementations because the numbers looked correct in isolation and the integrated result felt wrong. That is normal. The work is in the tuning, not the architecture.