thoosie

The premise

You draw a track freehand. thoosie turns it into a rideable coaster and runs real physics on it — speed, vertical G, airtime, inversions — then lets you ride it from the train.

The whole design problem is the gap between those two things. Drawing is loose and expressive. Physics is unforgiving. A line that looks great is often a ride that either stalls out halfway up the hill or pulls G-forces that would put a person in the hospital. The app has to let people draw freely and still produce something that works.

What I built

A full track editor: freehand, straight, and arc tools, plus a library of prefab elements — first drops, vertical loops, camelbacks, bunny hops, valleys, barrel rolls, half loops, Immelmanns, dive loops. Track types that behave differently under the physics sim: chain lift, launch, brake run, and trigger track.

A trigger and reaction system, so pieces can respond to the train passing — a brake run that holds the train, counts down, then launches it onward, or track that physically moves between two positions when a trigger fires. That turned the editor from a drawing tool into something closer to a small state machine, and it's the feature that made people build things I didn't anticipate.

Live physics telemetry surfaced during the ride: current speed, vertical G, airtime accumulating in real time, then a summary — height, top speed, max and min G, inversions, length, ride time.

Plus the unglamorous half: autosave, cross-platform level sharing, a gallery, a tutorial, a content filter on shared coasters, and a full mobile pass.

The decision that mattered

The physics readouts started as debug output. I kept them and made them a first-class part of the interface, because watching airtime tick up while you're cresting a hill you drew is the thing that makes the feedback loop work. Players learn what makes a good coaster by watching the numbers respond, not by reading a rule.

It's the same instinct as DrawEvolve, honestly — the system's job is to teach you to get better, not to do it for you.

What I cut

I built the game to run inside Reddit as a Devvit app and then didn't ship it there. Two platforms meant two sets of layout bugs, two embed environments, and a mobile letterboxing problem I'd have owned indefinitely. I shipped the standalone web build only.

Cutting a finished platform is unpleasant. It was the right call — the standalone build launched a day early and I spent that time on the game instead of on embed CSS.

Outcome

Launched August 2026. Promoted through the coaster and indie dev communities with a single gameplay clip.

The response I actually cared about: two testers played for twenty-five minutes unprompted, without being asked to and without stopping to give feedback. For a physics toy with no goals, no score, and no progression, that's the only signal that means anything.