
About Underrun
Neon corridors close in from every direction as you blast through procedurally generated levels, switching weapons on the fly and trying not to die. Underrun is a twin-stick shooter — move with one stick, aim and fire with the other — where each run reshuffles the layout, so memorizing rooms won't save you. The visual style leans hard into glowing retro geometry, all dark backgrounds and sharp color against the chaos.
The technical footnote is genuinely worth knowing: the entire game fits inside 13 kilobytes of JavaScript and WebGL, built as a games competition entry for the js13k challenge. Nothing is cut-down or placeholder — it just happens to be extraordinarily compact code. If you enjoy fast, WebGL-driven action, HexGL Racing goes in a different direction but shares the same browser-native 3D approach.
A mouse and keyboard is the most comfortable setup here, since the twin-stick controls map cleanly to WASD plus mouse aim — touchscreen play is possible but tight corridors make precision harder.
How to use
• Use WASD or arrow keys to move your character through the facility • Click mouse to shoot at enemies and obstacles • Your objective is to find and activate computer terminals to progress through levels • Collect health pickups (green items) to restore your health when damaged • Fight various enemies including spiders and automated sentries that will attack on sight • Look for plasma weapons and upgrades scattered throughout the levels • Each terminal you activate may unlock new areas or advance the story • Watch your health bar - if it reaches zero, you'll need to restart the current level • The facility has multiple floors and areas to explore • Some doors and passages only open after completing certain objectives
Reviews
No written reviews yet. Be the first!
More from Games

Tap to flap through the pipes! Features a global leaderboard, cloud-saved personal bests, and smooth mobile-first gameplay.
by Launch Arcade

A sweet physics drop-merge game where you launch candies upward into a growing pile. Match identical treats to merge them into bigger, more delicious sweets — and watch for special drops that clear whole columns or blast the board. Keep the pile from overflowing before the shop closes!
by alustriel92





