Metal Mutant

Side-scrolling action-adventure game developed and published for MS-DOS, Amiga and Atari ST by Silmarils and released in 1991. It is similar to Game Arts' Thexder in that it allows you to transform at any time into three different robot forms (Cyborg, Dino and Tank) You control Metal Mutant, the ultimate battle machine, which was sent to the heavily protected high-tech planet Kronox to find and destroy the tyrant AROD 7. On the way to this goal, you need to solve puzzles and combat hostile lifeforms and enemy robots. Source: Wikipedia, "Metal Mutant", available under the CC-BY-SA License.