Holloween thoughts

The game is ok and all but my problem and only reason I didnt give this game 4or5 stars is simply because I cant open any of the monsters other powers ? It say would u like to open this power for 800 food and then it does nothing after that no matter how much I tap or no matter that I have more than enough food to open that specific power which obviously Im going to need in order to stay in the challenge so please tell me how to open my monsters other and much better powers because theres four powers and I only have access to two (help) Im on level 29 about to be level 30

Maft1 about Halloween World - City Builder, v6.50