I love the game. Awesome concept and I thought "it'd be so cool to have something like that irl", few days later Meta anounces something that seems to be of the same concept as in-game.
Anyways, I think I can imagine a solution. I'd also very happily offer to help with it, however all I could do would be providing a website and a server to host it. Here goes the idea: you could split it into segments like DLCs. The player then had the chance of finishing segment 1, download the DLC/Segment 2 which would then replace the original game file but keep things like gallery scenes unlocked. That way you could bypass the 2 Gigs limit and wouldn't have to compress it any further.