BELTRUNNER — A Game Design Postmortem by Matt Sephton
Matt Sephton built BELTRUNNER for GMTK Jam 2026 as roughly 1,300 lines on Jinks, the small engine he is developing. It opens looking exactly like Asteroids, then drops the floor out: clear wave 1 and a black hole tears open where the next wave of rocks should be. What follows is a countdown race through numbered gates, in descending order, with time as the only resource. The postmortem is unusually specific about which ideas earned their place: ...