ACID
SIEGE
Falling-sand siege warfare
Rain acid, lava, nukes, antimatter and twenty escalating super-weapons on the enemy city. Fortify your own walls, climb the weapon ladder, and out-siege your rival. Runs entirely in your browser.
No install · No sign-up · Free
Original sand engine
A from-scratch cellular automaton — sand slides, liquids flow, solids stack, and chemicals react.
40+ weapons
From acid and fire to TNT, nukes, antimatter, black holes and an Annihilation Core.
Build & defend
Spend coins on City Blocks, brush upgrades and exponential armor to keep your city standing.
Online 1v1
Authoritative server, shared arena, live chat — siege a real opponent in real time.