RetroGaming Shorts Part 018 - Nemo 1983 Andrew Key Continental Software
Nemo 1983 (Memotech MTX)
I haven't found much info on this game, but it's plainly a clone of Jeff Minter's Gridrunner ... but rethemed to an ocean setting and with terrain that mixes things up.
I actually love the retheme ... you've got shark fins for the main enemies, and the green water is ... eh, okay I don't know what's up with that.
The MTX had hardware similar to MSX, but I don't know whether Nemo had any port to MSX or other similar hardware (such as ColecoVision/Adam).