You played tower defense game before, right? Build towers. The towers shoot creeps. Get more money, build more towers. Shoot more creeps?.
Progress is automatically saved. There is no penalty for escaped creeps, so you can leave it running all night if you want.
Upgrade costs are proportional to DPS*Area of the tower, so don?t buy upgrades you don?t need. There is no maximum damage for a tower.
Shotcut keys:
Shift-click to place multiple towers.
M ? Toggle music
S ? Toggle sound
1,2,3,4 ? Buy tower.
Shift-1,2,3,4 ? Change background
The game is paused in the menu.
You can click on the wave markers to make the next wave appear early.