I did this yesterday along with the Z stuff.
Journey to Silius / RAF world (Rough world?) - Sunsoft
Ref: There are no (good) sprite sheets. I doodled these while watching a 'let's play' (pausing for ref shots) and listening to the excellent music.
This game was apparently intended to be based on Terminator. The story seems to have been changed last minute or something, and it doesn't really work with the gameplay. The main character (only character) is pretty flat too.
Perhaps some dimension can be brought to the main character if it's revealed that he's actually a machine built by his father, and that the father also made the terrorist robots by mistake (and that they killed him). That would give the ending some tension, with the main character finding out that he killed his own kind, or that he needs to insist that he's different from them. Maybe the terrorist robots only wanted their own lot in the universe. Maybe the main character has... a... ssssisstahh?
So, yeah, I made the main character into a chibi thing, again. There are 3 or 4 versions of the main character. The Japanese cover, the Japanese sprite, the US sprite (no helmet and more chibi), The EU sprite (same as the Japanese one, I think). There might be some art in the instruction booklets too, but I have not researched that far yet. Anyways, other than basic use of colors, I didn't stay close to any design in particular. The Japanese armoured version has more blue on it, and the US one has a more white baggy pants look.
The enemies I just made quick roughs of. While the designs in the game are really haphazard, I think there is a fun thing going on with the white nonsense lump look.
I'd love to turn this into a 'metroidvania'.
Edit: Added a rough of the US main character. He's got some kind of thing going on with a black bar over his chest. I interpret that as some kind of hole/shadow under a collar of some sort.