There's a couple things I don't like about this game. Even the fully upgraded and max power "cannon" is weaker than the nuke accelerator. The accelerator should be a help but not your main propellant. Another is the game is a bit too easy. You can beat the game in 30-45 mins easily. Nonetheless, the game is still a 3/5.
Rate this up so ppl can see! Easiest way to win the game!!! Play through lvl 4-6 and but the extra cannons then play survival mode until you have enough $$$ to buy the upgrades and there you go!
i think lvl 21 was harder than 22,23, or 24 but that just me beat the game with 2208 left on just lvl 24 so i gotta get some more cash for other hard badges cuz i only got 6k