@:MaSaXi: Why not start a project yourself? You seem to know a lot about what can and cannot be done on MSX. Just start with some concept stuff (story, script, gameplay, some early gfx and perhaps some animations). You'd might interest other people in helping with development. MSX is the perfect if-you-want-it-then-you-can-make-it-yourself computer system.
I did the same with MOAM. 
Marble Madness and/or Gyroscope conversion or clone in SCREEN 1. Surely doable. 
if someone can do 2 pixel scrolling in SCREEN 1, I really don´t care if there are some colourclash on edge of ravines as long as game scrolls smoothly enough. It may be playable with 4 pixel scrolling too... as Spectrum Gyroscope was FLIP-SCREEN based.... and it was still somewhat playable...
There are NO such like games for MSX like Marble Madness! 
MSX2 conversion is nice too of course, but I feel there is bit more challenge to make it for MSX-1, I think.
Should this not be relatively easy on MSX2? It's a tile based vertically scrolling game... Why was this never ported to MSX2??
Wow, if we are resurrecting this old thread, I'm going to add my wishlist (some of which I'd love to do myself):
- I loved "Nether Earth" in the Spectrum, but there is no MSX game like that. I've always dreamed of a "Nether Earth 2", which I'd love to see in MSX (I'm not very interested in a port of the original, as if I wanted to play it, I can already play it in spectrum ;), but a sequel would be amazing ).
- I'd also love to see some point-and-clicks, Maniac Mansion style. There is "Stan the dreamer", but I don't think there's many more. Or even something more puzzle-y like Gobliiins would be awesome.
- and finally, more rogue-likes. There's Deep Dungeon Adventure, and z80rogue, but we can always have more :)