Scenario / Explorations Theme Swap

Re-theme a game for special occasions. Halloween and Christmas, playable

Theme Swap.

Same game.
Any occasion.

Change the theme of your game for any occasion with the Scenario MCP and GPT Image 2.5: every cat, background,
button and medal edited in place and dropped back in. Pick a theme, play it, and slide to compare.

Game …

How it was made

One game, two new themes, 585 CU.

Made with Claude Code, the Scenario MCP and GPT Image 2.5. Change the theme of your game for any occasion: every character, background, button and medal of Tower of Cats re-themed for Halloween and for Christmas, every layout kept so the new art drops straight back into the game, and two playable editions.

  1. 1

    Start from your game

    Tower of Cats has six cats in four poses, a meadow, a stump, islands, a catship, a bird, a moon, a UI kit, a logo, two medals and a music loop. Every picture lives in Scenario, and the game's rules never change.

    Input the game's own pictures

  2. 2

    Make one sheet per theme

    The character sheet is redrawn as a Halloween and as a Christmas edition: the same cats in the same places, each with one costume piece on the head or neck, so the bodies (the hitboxes) stay the same. This sheet is the theme's .

    With GPT Image 2.5 Sunburst · 13 CU a sheet

  3. 3

    Edit every picture, don't redraw it

    Each regular picture goes in as the first reference and the theme's sheet as the second, on the same canvas size. The prompt lists everything that must stay (the canvas, positions, sizes, poses, framing) and changes only the theme. Fifteen pictures per theme, and for Christmas one more: its meadow at night.

    With GPT Image 2.5 Sunburst · 12 to 17 CU a picture

  4. 4

    Cut where the regular pieces are

    A script cuts each themed sheet using the regular sheet's pieces: every painted pixel goes to the nearest regular piece, so a hat stays with its cat. The pieces keep the regular file names, and each one's is recorded.

    With Claude Code · Python

  5. 5

    Give each theme its music

    A new loop per theme, with a clear melody that repeats, cut to exactly 24 bars at 100 BPM with a short crossfade so it loops without a seam. The sound effects are shared.

    With ElevenLabs Music v2.5 · 60 CU a loop · ffmpeg

  6. 6

    Swap it in, then check

    The game loads the theme's folder (from its title screen, or ?theme= in the address), with its own sky: a purple dusk for Halloween, a moonlit night with falling snow for Christmas. The rules don't change, so both editions play straight away. A before and after slider checks every piece against the regular one.

    With Claude Code · Playwright

References and prompts

Every generation of the two themes. The edit prompts are shown rewritten as one standalone prompt for the final picture (the theme part is word for word); the sheet and music prompts are copied from the job records. The regular theme's own prompts follow for reference.

What did not work

  • The first Halloween set was painted from scratch. It looked right, but nothing lined up with the game. Editing each regular picture, with the theme's sheet as a second reference, kept every position and size.
  • Bats, holly and snowflakes painted inside the button and card frames were stretched with them. The frames are rebuilt from the regular ones in the theme's colours.
  • The theme's stylesheet repeated the whole border style and reset the button corner sizes, which squared the PLAY button. It now swaps only the pictures.
  • Browsers kept old copies of the art. Every themed file now carries a version code.
  • The first themed loops felt flat. New prompts asked for a clear, catchy melody that repeats.

Tip

Edit, don't redraw: pass the original picture first and the theme's sheet second, and list everything that must stay.

Credits

585 CU

35 finished generations for the two themes, final results only: 33 pictures and 2 music loops. 2 models.

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