R reload · Q shop · Esc pause (with a Restart option)
On a touch device, pick Touch (Joystick) below for an on-screen joystick, tap-to-shoot, and Reload/Shop/Pause buttons.
Difficulty
Easy, Medium, or Hard below tunes the math questions, the bot's aggressiveness, and scrap payouts (Easy pays more, Hard a bit less).
Easy is addition/subtraction only. Medium adds simple multiplication/division (factors up to 5). Hard uses the full range of all four, growing as you answer well.
On Hard, the game keeps running while you answer a question instead of pausing — everything else keeps moving.
The Math Twist
Reloading and shop purchases both require answering a quick math question against a 10s timer — fast, correct answers pay the most scraps.
On Easy, a first-try answer grants a free 10-second power-up instead of scraps, and missing 3 times in a row just grants you the reload/purchase anyway, no reward.
On Medium and Hard there's no free pass — you'll keep getting asked until you solve it.
Blocks & Scraps
Wood, brick, stone and metal blocks are scattered on the field — tougher tiers take more hits (or a stronger cannon) but pay out more scraps when destroyed.
Supply Depot
Spend scraps (Q) on more ammo, armor, a repair kit, speed, or cannon power — or place your own defensive barrier blocks.
The Enemy Bot
It farms blocks, fights back if you get close, and will periodically push to attack your base — don't leave it undefended!
Destroyed tanks respawn back at their base after a few seconds.