there needs to be a better uber weapon, because a 1 shot 1 kill thing is not enough when you have like 800 creatures a wave, and moing boy is right, you should be able to fire from your fort, it's pretty much useless otherwise.... honestly....
should have more upgrades, and you should be able to use all your stuff at the same time, would make it worth it to actually use anything other than the big bomb (those should have upgrades too.)