Sel said on his itch.io profile that LiL is like less than 20 or 25% (I can remember the exact amount) complete. I wonder how much of the game the "true route" is ?
Phase 1 -- harem route. We are here. By Sel's words, it will never be a true harem, but this part of the game is the closest we're going to get to one. Consider it a subversion of the trope rather than an actual harem.
Phase 2 -- dark phase. We're seeing hints of it, but we're not there yet. Expect heads to roll. Literally. I suspect that will start the next time Winter starts.
Phase 3 -- Purity routes. These are individual one-girl endings that will be added one at a time in a more or less random order. When a girl's route is completed, the game will kick you back to the selection point so you can pick a different girl.
Phase4 -- True ending. Only available after seeing all purity routes.
He has outright stated the true ending is not a harem ending. It will probably be a breaking of the cycle and resolution to the Happy arc (conjecture on my part)
I would guess that each purity route that gets added will be a full update's worth of content, and there will probably be purity routes for all 20 main girls and some of the side girls (Niki, Sara and Karin would make sense for purity routes. Yuki, Maki, and the children less so)
Based on the percentages Sel has given so far, Harem route will probably be up to %40 of the game, and dark route about as much.