Kuggazer
When you make a game in parts, you lose at least half of the players. I don't know anybody who really want a splilt game.
Also,
When you make a game in parts, every project (part) has its own versioning. You cannot make a part 1 up to version 0.3.0 and then call the first release of part 2 v0.3.1 or whatever. (There is nothing called 0.31, it is 0.3.1).
Doing it like this confuses people, it's not possible to figure out what to start with etc., also:
Also, you cannot carry over savegames (without issues). You have to start each game up again.
Why the freaking fuck even split the game in the first place? If it's because you're afraid of the size, either compress well enough to not provide much lower quality video/pictures. Or, use a proper game engine.
The game sounds interesting, but I don't want to nor have time to get four games which is essentially one game.