I personally helped develop a game with an entire inventory/crafting system, and an isometric map. Final product never saw the light of day, sadly.

People have made some pretty slick turn-based combat systems. Some deck builders, others more spellcasting/mana oriented.

And it's renpy so like 80% of the games are straight up porn, so I'm not naming a single one here lol.

I really enjoyed Roadwarden. Interesting take on an old fantasy genre and gave me “this is ancient history” vibes. I’m not usually into visual novels but beat this game. It’s available for under $3 right now, I am showing 20 hours played, totally worth it.

https://store.steampowered.com/app/1155970/Roadwarden/

"Analogue: A Hate Story" and its sequel do some technically interesting things, and they both also have interesting stories, I can recommend them.

http://ahatestory.com/