PAUSED
Choose a battlefield
Enemies ("Glitches") spawn from the orange portal and follow the path to the blue portal. Each one that gets through costs you a life — lose them all and it's game over. Build towers on any open grid cell off the path to shoot enemies as they pass. Survive wave 50, with a unique boss every 5th wave, to win.
Click a tower in the shop, then click an open cell to place it (right-click, or click the shop entry again, to cancel). Click any placed tower to select it — the sidebar shows its stats and Upgrade/Sell buttons.
Upgrading costs money and raises a tower from level 1 to level 10, improving its range, damage, and other stats each step — costs rise with level. Selling refunds 55% of everything you've spent on that tower (base cost plus every upgrade).
Every boss kill drops one boost token, shown at the top of the screen. Select any tower and a "Use Boost Token" button appears above Upgrade — click it to instantly raise that tower one level for free, no money spent. It's hidden once the tower hits level 10 (or you're out of tokens), so you can't waste one.
The Virus Injector doesn't hit hard directly — every hit infects its target with a virus stack instead. Each stack deals its own damage per second for the rest of that enemy's life, so repeated hits pile stacks up and ramp damage fast, permanently. Stacks cap out per enemy, so steady fire on one target beats spreading shots around — it's especially strong against tanky enemies and bosses. A stack's damage is locked in at the tower's level when it lands, so upgrading mid-fight makes future stacks hit harder without changing ones already ticking.
Traps go on the path itself, not beside it. Each one fires exactly once — the first enemy to reach it sets it off, hitting every enemy currently in its blast radius, then it's gone. Slow and Freeze traps briefly cut enemy speed (Freeze stops them cold, for less time); Rewind traps shove enemies back along the path, undoing their progress.