Make a jump-and-run game by describing it to a platformer game maker

A platformer game maker lets you build a jump-and-run game, where a character runs, jumps between platforms, avoids hazards and reaches a goal. With an AI platformer game maker like VibeDream you do not draw tiles or write physics code: you describe the character and the rules, play the first version in a live preview, and tune it by chatting until the jumping feels right. Platformers are harder to get right than arcade games, because one bad jump makes the whole game feel broken. Most of this guide is about the jump.

What you will make

The example we use is a cat that hops across clouds to collect fish. It has everything a small platformer needs, and nothing more:

• A title screen with the name, a one-line goal and TAP TO PLAY.
• A cat that runs left and right and jumps only when it is standing on something.
• Clouds as platforms, some of them moving, at different heights.
• Fish to collect, each worth points, and a score that is always on screen.
• A fail state: fall off the bottom of the screen and the run ends.
• A game over screen with your score and your best score, saved in the browser.

VibeDream builds games with Phaser 3 and its Arcade Physics, which handles gravity and collisions. The template only lets a character jump while its body is touching the ground, so double jumps are something you ask for, not a bug you get. Games are portrait first, so they fit a phone held upright, and they also play with the keyboard on a laptop. Art is drawn in code with shapes and colours unless you attach your own pictures.

Because it is a browser game, the finished platformer is just a link. There is nothing to install for you or for the people who play it. If you want to know how browser games differ from app store games, our HTML5 game maker guide explains the trade-offs in plain terms, including what to look for on phones and where you can host the result.

The prompt

Paste this into a new project, or change the nouns to make it yours:

A platformer where a small orange cat jumps between white clouds to collect fish. The cat runs left and right and jumps with one button. Some clouds drift side to side. The screen scrolls upward as the cat climbs. Each fish is 10 points. Falling off the bottom ends the run. Show the score at the top and the best score on the game over screen. Soft blue sky, bright colours.

Why this prompt works: it names the hero, the platforms, the collectible, the controls (move plus one jump button), the camera (scrolls upward), the scoring and how you lose. Each of those is a decision the AI would otherwise make for you. If you leave them out, you still get a game, just not your game.

Swap the theme, keep the rules

• A frog hopping lily pads to catch flies, with the pond scrolling sideways.
• A robot climbing a factory tower, collecting bolts, with steam vents as hazards.
• Your kid's drawing of a dog jumping over garden fences to reach bones. Attach the drawing so the AI can match the colours.

Make the jump feel good

Platformers live or die on how the jump feels. The good news is that you can tune it in plain words. Change one thing at a time and play after each change.

• Floaty jump: ask for stronger gravity, or a faster fall than rise. A jump that comes down quicker than it goes up feels snappier.
• Jump too short to reach platforms: ask for a higher jump, or for platforms to be closer together. Changing the level is often better than changing the physics.
• Hard to control in the air: ask for more air control, so the player can steer while jumping.
• Missed jumps at the edge of a platform: ask for a short grace time, so the player can still jump a moment after running off a ledge. Game designers call this coyote time.
• Want more skill: ask for a variable jump, where holding the button longer jumps higher.
• Sliding around: ask for the character to stop faster when you let go.

Write your requests the way you would say them to a friend. Make the cat fall faster and jump a bit higher is a perfectly good prompt.

Levels and difficulty

A first version usually has one endless area. When the core jump feels good, add structure. Here are prompts that work well, one at a time:

• Add three levels. Level 1 has only still clouds, level 2 adds moving clouds, level 3 adds clouds that vanish a second after you land.
• Show a level complete screen when the cat reaches a golden fish at the top.
• Add a simple enemy: a bird that flies left and right. Touching it ends the run, jumping on it bounces the cat up and scores 50.
• Make the screen scroll a little faster every 30 seconds.
• Add a checkpoint flag halfway up each level.

A good rule from game design: introduce one new idea per level, let the player try it safely, then test it. If you add moving platforms and enemies in the same level, players will not know what killed them.

Touch controls for phones

Most people will play your game on a phone. Platformers are hard to control with tiny on-screen arrows, so VibeDream games use controls built for thumbs:

• Drag anywhere on the left side to move, like a joystick that appears where your thumb lands.
• A large action button for jump, placed where your other thumb rests.
• Arrow keys or WASD to move and space to jump on a laptop, in the same game.

If the controls feel off, say so. Make the jump button bigger, or move the jump button to the bottom right, are normal requests. Test on a real phone before you share, since the preview phone view is close but not the same as a thumb on glass. Our guide on making a game on your phone covers building the whole thing from a phone.

Share it and let people beat your score

A leaderboard only works if the score means the same thing for everyone. In a platformer that usually means height climbed or fish collected, not time spent, because a slow careful player should not beat a fast one by waiting. Ask for the score you want in plain words, such as score is the highest cloud reached times 10.

When it plays well, press Put it online. It costs 5 credits and gives the game a link and a play page with the top scores beside it. Players who sign in can remix it into their own copy, which is a nice way to let a friend design a harder level. The getting started guide shows each step.

Bugs first platformers usually have

These come up again and again in AI-made platformers, and each one has a short fix you can paste.

• A platform you cannot reach. Ask for every platform to be reachable with one jump from the one below it, then climb the level yourself.
• Falling through moving platforms. Ask for the cat to ride moving clouds, so the platform carries it instead of sliding out from under it.
• The camera leaving the player behind. If the screen scrolls on a timer, ask for it to pause while the cat is near the bottom edge, or to follow the cat instead.
• Fish placed where you cannot see them. Ask for collectibles to spawn only inside the visible screen.
• The jump button covering the level. On a phone the button sits over part of the screen, so ask for platforms to stay out of the bottom corner.

When to use a different tool

• If you want a big platformer with hand-made levels and pixel art, a dedicated engine with a level editor will serve you better over time.
• If you want to learn to code platformers, write one in Phaser yourself. Our Phaser 3 explainer shows the structure.
• If you want something faster to make, with shorter rounds, an arcade game like a dodger might be a better first project.
• If you need a native app store game, a browser platformer is not that. VibeDream games run in the browser on phones and computers.