I loved the game; it's simple, fun, and exciting.
Suggestions:
I'm considering that the content will be greatly expanded, so I won't focus on anything I believe will be in the game, like more spy scenes or the like.
- (Essential) Please add an item like "Cave Explorer's Goggles" or some new brightness mechanic. Monsters could even use magic that increases brightness. Seeing only shadows/outlines at first is exciting, but after a certain point, it gets repetitive. I think if there was a way to keep the brightness at a minimum of 15% and keep things happening, it would be very stimulating. It could be an option in the preferences too, but I'd find it more immersive with something like the goggles.
- Personally, I found the game too difficult. I think some leveling mechanics for the MC should be added. Or at least armor.
- Clothes and costumes you can buy for Aster. Bunny, Nurse, Sexy Witch, Goth Slut. At the salon to get her hair done, dyed, or get special makeup done "for the MC."
- More lines; after cumming, she could make comments like, "I think someone's trapped here."
- After losing a dungeon, you could have flashbacks that worsen with Aster's depravity, of her having sex with her mentor and then saying it was a nightmare.
- At high levels of depravity, Aster could have sex with monsters, perhaps after losing the dungeon, and her mentor enjoys it.
- At high levels of depravity and with a lot of money left, some of the money could disappear and Aster could appear with bigger breasts, ass, and thighs, saying it was a side effect of magic and the money was given the money to starving orphans. This is cool because it adds a new perspective to the late game.
- Perhaps there could be a mechanic for Aster's affection for the MC based on the ratio of wins to losses. Does that prevent anything? No. But it could change the dialogue and how much Aster tries to pretend/lie about the obvious or rub it in the MC's face. This would add two possible NTR types and would please many fans, without relying on difficult implementations (I think), just one variant and scripted dialogue (50% of an NTR game, as a rule, consists of dialogue, not necessarily long, but well-crafted).
I'll come back here if I have any more suggestions. I hope they're good and implementable, one way or another. You already have gold in hand. Congratulations on the idea and the project!