Maybe a different arena map where your penguin fight can be added. We can train our penguin to fight. Maybe we can gain some skill points when we level up.
Some upgrades done instantly by cash OK. Play continuously by cash OK. Levelling up without exp OK. But can only produce some items I researched by paying cash to elements NO.
DKC10000 What do you think with your comment? All of the games in the world DONE FOR MONEY. And there hundreds of tower defense fans in this site. And can you work on a game for weeks just for fun? Yes I agree with you in one point; there are alot of tower defense games but good ones succeed and the bad ones forgotten.