For starters i know that SUPERALEX has been slow. Very slow, but i also understand that he had to remake a lot of things to transition the game from a VN to a Free-roam game, i think that in itself took a long amount of time/effort. Plus he was working alone, but not anymore, I hear he hired 2 more people (they are still in training) to help with development.
The size of his games are a little concerning too, they have a history of beign BIG, there are like 6 scenes and the size is already 6Gb, could be that he uses 100% uncompressed images, but no one can deny the quality of them, they are one of the best renders I have seen in a game.
I don't understand why he wants to add so many characters in this game as well, i remember reading in his patreon page that he plans on adding like 60+ characters, that's a LOT, more characters than a lot of other AAA (if thats a thing lol) porn games
But I see a very promising future for this game, one thing i think he will need to do is change the naming system, many people must read 0.8 and think the game is 80% complete, which is far from the truth, but anyways.
I really like the game, the characters so far and the setting, and I would like to recommend the game right now, but I do give this advice with a warning that the game is not yet loaded with sex content and stuff, so if you just want the sex and stuff wait a little more for other updates.
Writing this as v0.8c