100MB is pretty tight; you probably have to look at compressed versions to get close with most games. If you can go a little higher you can get some real good ones with a good amount of gameplay.
Text based games like
News Desk or
Sistersitting might be good options.
Bell Master only 38MB
My New Roommate has a pretty good rating but I haven't played it. Only 62MB for the compressed version
Deviant Discoveries has the light and ultralight versions which are 111MB and 56MB respectively
Rogue-like Evolution is really good and depending on the version you get can actually be under 100MB. The expanded mod is a bigger download but I think it's worth it.
Shag the Hag compressed is only 93MB and it's a good, completed game
Triangle is also a good one and completed, 125MB compressed version
Hack n' Stalk 2 196MB
Monster Girl Club Bifrost is actually the first game I thought of. It's 350MB but lots of repeatable gameplay so a pretty good way to kill lots of time.
I'm gonna include plugs for the games in my signature.
Element-174 its compressed version is 362MB and it has a ton of different routes so lots of replayability.
What's mine is yours has 3 seasons and each is less than 200MB compressed. It's pretty much straight forward kinetic novel, no real choices but I love it.
