Pengon

Just as the name implies, Pengon is a clone of Sega/Coreland's old arcade game, Pengo. You play Willy the penguin, who is trapped in a maze filled with dangerous mutant sea lions. Willy's only defense is to push the blocks of ice that the screen is made up of, so that the blocks hit the sea lions and crush them against the walls.

Of note is the difference between the versions; the original program was made in America for the Tandy Colour, then ported to Dragon 32 and published by Microdeal, who liked the name enough to put it on Pengo clones for the Commodore and Atari which graphically have little in common with the CoCo game.