I think the agility system may not be working correctly. The tortoises only have 10 agility, I have over 60. I kill them in one hit, but for some reason they hit me before I kill them.
Your upgrading system is still messed up. You can't make the first upgrade the same increase in power as the last upgrade and charge more money for the last one. This just promotes filling up every square with a level 1 tower.
VoltesV beat me to it...you can beat the entire game by building one single arrow tower and upgrading it to the max. And please make a faster game speed, it's still to slow.
 "The Enchanted Cave"){kind=icon}
 "Protector III"){kind=icon}
 "The Horde"){kind=icon}