📱 Mobile2010ZeptoLabHARDCut the Rope rebuild deck
HARD
The Verlet rope solves itself in a weekend and then the project is forty puzzles that each turn on one timing insight, which you find by playing your own levels rather than by writing anything.
You will get the loop working. Then the real work starts.
Rope physics is a solved problem and an agent will get you most of the way there in one shot. The swipe-intersection test is what to check on day one, because a point-based cut only fails on fast swipes, which means it survives your careful testing and then breaks for everyone with a real thumb. After that the actual job begins: each puzzle needs one non-obvious timing insight, and discovering that you need forty of those is the moment you understand what ZeptoLab was actually selling.
- Difficulty
- HARD · 3 of 5
- First playable
- A weekend
- The original
- 3 team-years
- Released
- 2010 · Mobile
- Genre
- Physics Puzzle
Build a physics puzzle in which a swinging payload hanging from ropes must be delivered to a target by cutting those ropes at the right moment. Single HTML file, Canvas 2D, hand-written Verlet physics, no build step. Requirements: - Ropes are Verlet constraint chains: 12 to 20 point masses each, distance constraints solved with at least 8 relaxation iterations per fixed 60Hz step. Spring-based ropes stretch like elastic and quietly make half your puzzles unsolvable. - Cutting: intersect the pointer's movement SEGMENT for this frame against each rope segment. A point-in-radius test misses on fast swipes, which means it passes your own testing and fails every real player. - Anchors are either static or attached to a point travelling a path defined in the level data. - Three helpers: a bubble applying constant lift until popped, a directional air puff, and a bouncy pad. Each is a small pure function of payload position and velocity. - Three collectible stars per level, placed so a naive straight drop misses at least one. - Levels live entirely in a JSON file: anchor positions, rope rest lengths, star positions, hazards, target. Ship 12 hand-authored levels, at least three of which need two ropes cut in sequence with different timing. - Starting constants: gravity 900 px/s squared, payload radius 24, point damping 0.99. Definition of done: I can three-star a level that requires cutting one rope, letting the swing build for a beat, then cutting the second at the top of the arc.
- Hundreds of hand-designed levels arranged on a difficulty curve you cannot reverse-engineer
- Om Nom, who is a real character with animation, plush toys and a cartoon series behind him
- The audio design, particularly the specific crunch when the sweet lands
- A decade of level packs, seasonal boxes and gently escalating mechanics
Verlet chains solved by distance constraints
Points, previous points and a relaxation loop give you rope, cloth, chains, hair and a grappling line out of the same thirty lines, and unlike springs they do not stretch when you hang something heavy off them. Springs are why half of everyone's rope puzzles quietly stop being solvable.
ScopeA weekend— build just this, not the game
Build a Verlet constraint sandbox. Single self-contained HTML file, Canvas 2D, hand-written physics, no libraries, no build step. - Each point stores position and previous position. Integrate as x += (x - prevX) * damping, then apply gravity. There is no velocity field anywhere. - Constraints are distance pairs, solved by moving both endpoints halfway to the rest length and repeating eight times per fixed 60Hz step. Pinned points ignore correction. - Three scenes: a 20-point rope pinned at one end carrying a heavy mass; a 20 by 14 cloth pinned along its top edge; and a chain pinned at both ends draping over two circular pegs, with points pushed back out of the circles positionally. - One anchor is draggable, so a chain has to follow a moving attachment without stretching. - Sliders for iteration count, gravity and damping, plus a wireframe view of the constraints. Definition of done: at eight iterations the loaded rope stretches under 2%, and at one iteration it visibly behaves like elastic.
Not a clone — Cut the Rope re-themed and cut down to something you can finish. The angle is the important reel: it is what turns a project into a weekend. 5,880 ways to land.
Abyssal Hands Off
Cut the Rope, but an auto-battler — you set up, it plays itself, set in an underwater civilisation. Rendered in risograph two-colour print.
Build a browser game called "Abyssal Hands Off". The pitch in one line: a physics puzzle in the spirit of Cut the Rope, but an auto-battler — you set up, it plays itself, set in an underwater civilisation. WHAT THIS IS Take the SHAPE of Cut the Rope — its core loop, and whatever makes that loop good — and rebuild it as your own game in a different world at a smaller scope. Use your own names, art and audio, which you want anyway: a reskin of somebody else's game is less interesting than a new one that works the same way. THE ANGLE — this is the important constraint, honour it above everything else An auto-battler — you set up, it plays itself. The player only makes decisions between rounds. Combat resolves deterministically from board state and seed, so a replay is exact. This is what makes the project finishable. If a decision would push the scope back towards the original's, take the smaller option every time. THE THEME An underwater civilisation. Pressure and oxygen as constant timers, near-total darkness outside a lamp cone, and sound as the main information channel. The theme is not a coat of paint. Let it change what the mechanics mean — a reload, a health pack and a locked door should all be things that make sense in this world and nowhere else. LOOK Risograph two-colour print. Two spot inks with visible misregistration, halftone dot shading, and paper texture showing through every fill. REQUIREMENTS - Runs in a browser with no build step. Canvas 2D unless the angle genuinely requires 3D, in which case three.js. - Fixed-timestep update loop with interpolated rendering, so it behaves the same at 60Hz and 144Hz. - Every tuning constant in one CONFIG object at the top, exposed as live sliders in a debug panel. You will find the feel by dragging those, not by prompting. - All content — levels, entities, balance numbers — in JSON or plain data files, never inline in the logic. - Audio generated with the Web Audio API rather than asset files. - Respect prefers-reduced-motion: keep the fades, drop the shake and the parallax. BUILD ORDER 1. The core loop with placeholder rectangles, at the reduced scope the angle demands. No theme, no art, no audio. Make it fun as rectangles first. 2. The angle's consequences. Cutting to bots, or to turn-based, or to one level changes the design rather than just shrinking it — find out how and rewrite step 1. 3. The theme, as content and data. 4. The look, applied last as a rendering layer over a game that already works. Start by writing a one-page plan: the core loop, what the angle removes and what that frees you to do properly, and what you are deliberately leaving out. Wait for me to approve it before writing code.
Half the time one of these already does what you wanted, and the other half it saves you a week of solving a problem someone documented in 1997.
One count per game. No account — it is tied to a salted hash of your IP, which is not stored in a form anyone can reverse. Every build adds 3 team-years to the counter on the homepage.
Then try these
Questions
How hard is Cut the Rope to rebuild with an AI agent?
Yes — every game is buildable at some scope. The question is how hard, and Cut the Rope is HARD (3 of 5). You will get the loop working. Then the real work starts. The Verlet rope solves itself in a weekend and then the project is forty puzzles that each turn on one timing insight, which you find by playing your own levels rather than by writing anything. Reckon on a weekend to something you can actually play — not to something that matches the 3 team-years ZeptoLab spent.
What makes Cut the Rope hard to rebuild?
The Verlet rope solves itself in a weekend and then the project is forty puzzles that each turn on one timing insight, which you find by playing your own levels rather than by writing anything. That is why it sits at HARD rather than a tier either side of it. If you want the idea without the project, the transferable part is verlet chains solved by distance constraints — a weekend of work.
How long does it take to build a Cut the Rope clone?
Wrong question, and it is worth saying why. Nobody rebuilds Cut the Rope — the original took ZeptoLab on the order of 3 team-years, released in 2010 on Mobile. What you can do is reach something playable and genuinely yours in about a weekend, and then keep going for as long as it stays interesting. Any figure that claims otherwise is measuring a prototype and calling it a game.
What do I lose by building my own Cut the Rope?
Hundreds of hand-designed levels arranged on a difficulty curve you cannot reverse-engineer. Om Nom, who is a real character with animation, plush toys and a cartoon series behind him. The audio design, particularly the specific crunch when the sweet lands. Those are the parts a prompt will not hand you.
Which AI coding agent should I use to build it?
Any of Claude Code, Codex or Cursor will handle this prompt. Paste it as your first message, let the agent scaffold the project, then iterate on feel — the second, third and tenth prompts are where a game actually gets good. Work in an empty folder or a fresh git branch so you can throw it away cheaply.
One email when new games go on the list. No other reason to email you, ever.