Cute little arcade game! You've got a title screen, in-game help, and end-of-game scoring. The randomized rules for each play are a nice touch. About the only thing I could ask for would be better visual feedback to show me when I grabbed/whacked the correct critter (like maybe extra sprites for each creature to show them being grabbed or whacked, or dodging an incorrect input). As is, you can only tell you've done the right thing by watching the score counter.