About Brain Gym

Brain Gym is a free, browser-based math puzzle game built around one simple idea: your brain deserves a workout that never repeats itself. Every puzzle you see is generated fresh, on the fly, by a procedural engine — no two grids are ever the same, and there is no final level. The game simply keeps climbing with you.

How the game works

Each stage presents a grid of numbers hiding a mathematical rule — vertical arithmetic, horizontal sweeps, order-of-operations gauntlets, spatial patterns, sequences, modular arithmetic, algebra, ciphers, and more. Your job is to crack the rule and fill in the missing value before the timer runs out. As you advance, grids grow, rules stack, and the countdown tightens.

Two paths are available from your very first game. Newbie introduces one rule type at a time in a clean, steady climb. Pro mixes surprise mechanics into puzzles from stage one and pushes to a higher ceiling — built for players who never want to feel fully comfortable. Both paths eventually reach Interleave Mode, an endgame where mechanics combine into compound challenges.

The IQ tracker

As you play, Brain Gym estimates a session IQ score from your stage progression, solving speed, and how often you lean on Time Grants. It's designed as a fun motivator, not a clinical measurement — a way to watch your sharpness trend upward as you practice.

Who builds this

Brain Gym is an indie project by HeyPN, a small independent studio building free, fast, browser-first web tools and games — including PDF utilities, QR generators, text-to-speech readers, and more. Everything HeyPN ships is designed to load instantly, work great on mobile, and respect your time. No downloads, no signups, no friction.

Get in touch

Found a bug, have a feature idea, or just beat your personal peak stage and want to brag? We'd genuinely like to hear it — head over to the contact page and drop us a message.