Metal Mutant! Yeeahh - Cyborg, Dinos, and Tank - Cyborg was a humanoid, whose main weapons were a club and fork. The Cyborg was also the form you had to take when saving the game (connecting to this spaceship-looking thing that was floating in the air). It was also the only form that could jump, and had a grapnel thing to climb onto higher ledges. Its walk-speed was the fastest.
The Dinos (probably my favourite) resembled a kind of Tyrannosaurus-shaped dinosaur. It could breathe fire, bite, shoot fire from its tail, use hypno-eyes (whetever they did), and could also make a little bug-drone thing come out of its back whicih you could then control and move around.
The Tank was the slowest-moving, and moved on caterpillar tracks. It could fire bullets horizontally, vertically, or diagonally (upwards), and fire rockets out of its "eyes".
We had a demo of it on the Atari, which was just the start of the game (in a green kind of swampy-forest place), but a few months ago I found and downloaded the full version on the Net and played it in DOSbox...however, I didn't get much further beyond the point the demo finishes, because it just got really hard and I went into this purple tunnel thing and got nubbled by these little bug...things.
But anyway, yeah, it was quite a fun game

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