¡Yay!, and now is being ported to MSX assembler by Karoshi, Wyz & company
This one remembers me that I think C could be a great development platform to create in a fast way a lot of games. Evenmore if there're other games programmed in C that could be easily ported using only some specific libraries (IIRC spectrum has his own sprite library, named spritepack or so). Some months ago I was playing with z88dk; but the MSX support only covers text console aplications (and not very complete btw, only a text adventure example that comes with the package compiles without glitches). The source code was a little mess too and I finally switch back to SDCC that seems to be easy to expand.