Thanks for all those ideas. I agree those ideas would be a great gamify step. There is a small hidden thing going on by the way, as you use hints currently there is a persistent count down going on. When you solve all animals, you are given a star rating based on how much you asked for hints, and there is a total time it took you from when you first started finding your first animal to when you've found them all.
I may or may not do more with that submission since I'm also working on another submission that will be a pac man type cat/mouse maze chase perhaps.
Thanks again for your comments and suggestions.