Claude Haiku 5.5: Can the Cheapest Claude Build Celeste's Jump?

The test

The prompt

Build one mechanic for a 2D side-view platformer in Godot: the jump. It has to feel as tight and forgiving as Celeste's. The player is a CharacterBody2D in the group player, drawn as a rectangle about 1 tile wide and 1.5 tiles tall. This pass is a grey-box in the clean, flat look of the reference picture: build everything from primitives, and don't download or generate any art or sound. The picture shows the look; where its layout differs from these words, build the words. The game is one room that fills a 1920 by 1080 screen, and the camera never moves. Lay the room out on a grid of 48-pixel tiles, 40 across and 22.5 down, counting columns from 0 at the left. The floor is the bottom 2.5 tiles of the screen, a solid wall closes each side, and there is no ceiling. From left to right: open floor from the left wall to column 10, with the player starting at column 3; at column 10 a step one tile high, after which the floor stays at that height to column 17, making a ledge; from column 17 to column 22 a gap 5 tiles wide that drops out of the bottom of the screen, wide enough that only a jump at full running speed clears it, and falling into it puts the player back at the start; then the floor again at its first height, all the way to the right wall. On that floor, at columns 25 and 26, stands a block 3 tiles tall. From column 32 to the right wall, a shelf one tile thick sticks out of the right wall with its underside 3 tiles above the floor, so its left end is a corner hanging over open floor. The player runs left and right at about 11 tiles a second: the left and right arrows or A and D run, Space jumps, and R puts the player back at the start. The jump is the point. A quick tap of jump is a short hop that gets up the step but not over the tall block, and holding it goes much higher, over the block. Running off the ledge and pressing jump a moment too late still jumps, but there is no jumping in mid-air after that. Pressing jump a moment before landing jumps the instant you land. The jump hangs for a moment at its peak. A jump whose head clips the shelf's corner by a few pixels slides past the corner and keeps going up instead of stopping. And you fall faster than you rise. Make every key above an input action so it can be pressed by name: move_left, move_right, jump and restart. Nothing else yet: no enemies, no pickups, no dash, no wall jump, no menus and no sound. The look comes in a later pass, so keep the scenes and scripts easy to build on. Run and test the game only through Flockbay's tools: flockbay_play, flockbay_run_headless, flockbay_script_errors, flockbay_game_input, flockbay_game_get, flockbay_game_set, flockbay_game_screenshot, flockbay_game_step, flockbay_game_time, flockbay_last_run and flockbay_stop. Don't start Godot from your own shell, and if one of those tools can't do something you need, say exactly what was missing in your handover. Playtest it yourself and hand it over when you think it's done.

What was judged

In the video