Eintagsfliege

I'm a little sad Success isn't making more VNs. Aoishiro was pretty much exactly my thing.

I am never NOT going to recommend Inganock, though it may not necessarily be the VN that best fits your criteria. It's very...abstract? Poetic? It's not easily described. Planetarian is one that's more focused on romance than action. Similarly, Yume Miru Kusuri's dark, and probably one of my favorite romance VNs, but it's not scifi/fantasy nor very action-packed. Maybe try Cross+Channel? Some people complain about the translation, but I still enjoyed Ixrec's version, at least.

Touma Mia of Duel Savior I could probably find others, but it would be unnecessary, because she's a condensation of everything I hate in a character.