Hustle Chumy is an SG-1000 and MSX game developed by Compile and released in 1984.
In Hustle Chumy players control a mouse named Chumy who needs to collect apples (and other food) in a sewer, avoiding other critters as he goes. As Chumy eats more food, his speed decreases, but his fireballs are given a longer range. Levels have varying layouts.
There are several types of enemies in the game, most of which can be defeated with fireballs.
Bats: Bats fly over Chumy.
Mecha-Dinos: Mecha-Dinos are indestructible, although Chumy can slow them down with fireballs.
Gators: Gators usually sleep in one spot, but sometimes move slowly around.
Cats: Cats can jump like Chumy.
Ninjas: Ninjas need to be hit with three fireballs to be defeated.