Amphibian!

Amphibian! is a sort of reverse Space Invaders; the player controls a frog who can climb an apple tree, and use his position to drop apples on roaming lizards below that will kill him if they touch. As the game progresses it not only gets faster but other creatures begin to affect the playfield; birds come in and drop the apples the player needs, and a predator climbs the tree forcing the player to jump off or move around quickly.