Donk!: The Samurai Duck!

Donk is an ordinary duck who benefits from having been raised by samurai
warriors, who’ve taught him everything they know about combat psychologies,
strategies and skills. To prove himself he has set off to collect crystals
from 112 levels of earth.

Once you collect the target quota of gems, you must escape from each level
through one of its many exits, giving the game a similar structure to Alien
Breed: Tower Assault. Magical powers can be collected along the way, including
the ability to turn into an inflatable toy duck, which makes it possible to
float across water. There is a simultaneous split-screen 2-player mode
included as well.