Fill-in

Fill-In is a puzzle platformer built around arithmetic and momentum. You start as 0 and pick up digits to build a multi-digit number. Which side digits attach to depends on which way you’re facing—so order and position both matter.

Growing your number changes how you move: more digits mean more mass and a lower jump, so every pickup is a tradeoff between power and mobility.

Boxes don’t all behave the same. Some only slide when your number is equal to theirs, greater (or less), a multiple or divisor, or something in between. The wrong value won’t budge them—plan your number before you commit.

Run through a tutorial and 10 hand-authored levels with platforming, splitting and merging digits, and level-themed challenges. Restart anytime with R (or the matching gamepad button).