GAMESLASHIn the Flow launches a watercolor physics game built with Claude-assisted code
By GameSlash
A new playable November 4 watercolor prototype simulates water flow and pigment on paper. Creator fortress-rhythm credits Claude for coding help, while retaining direct control of the painting design.
Fortress-rhythm released the playable In the Flow prototype on itch.io on November 4, 2026 at 08:26 UTC. This is a browser watercolor simulation, not an AI image generator: instead of choosing a digital brush that simply blends pixels, players control pigment and water, then wait for them to move and dry.
A simulation where drying time is the tool
The developer describes a 160-by-120 grid updated 60 times per second. Water moves through wet paper, carries pigment, evaporates, darkens edges and allows dry color to lift when wet again. Commissions ask for effects such as gradients, clouds or water rings, which are graded by properties like edge softness and evenness rather than by tracing a picture exactly.
What can players try now?
The HTML5 prototype is playable on itch.io, best on desktop with mouse or pen, and also supports touch. Players pick water or pigment, choose strength, paint, inspect damp areas with a lamp, speed up drying, and deliver commissions. The creator flags limitations in glazing and lifting dry pigment; the larger seasonal commission-shop game remains a future plan, not a released feature.
What part was AI-assisted?
According to the developer, Claude assisted with code, code-drawn interface items, help and hint text, and procedurally generated sound. The developer says the design, simulation tuning, levels, reference paintings and paper photograph are their own. It was made for Game Gauntlet's SIM Jam ending November 4. GameSlash has not conducted an independent gameplay test.
Primary source: In the Flow official itch.io page.