Hey! Glad you liked Lucky Kiss!
To unlock this scene with Riya, you need to:
1) complete all previous quests with her
2) raise your relationship with Riya to at least 30
3) buy a special potion in the store
4) slip Riya the potion at the very beginning of the game
5) win her in the game
There are ways to cheat in minigames, but there are no such ways in the dungeon. Don't forget to level up your stats, and the dungeon will be easy on any difficulty.
I'll check out the game with Riya. A lot depends on the difficulty level, and I intentionally made the easy level very easy, since many people complain about the difficulty.
Regarding the Patreon code, please wait for the next update.
Yes, I try to spend a lot of time refining the locations to make them beautiful, thank you!