Excellent game! Great art, good dialogue. A bit grindy.
My suggestions:
1. Less griding with Nel. You reach level/money cap easily enough and then you just have to repeat again and again
2. Item to double or tripple EXP gain for lowest level party member. It takes forever to level them up and they are useless at lower levels.
3. Items for futa mode (no balls/scrotum). For special scenes/events. Can be explained by using up all your mana or something. Not sure if it would be worth it as a full mode... The penis is easy enough to add as another layer (like clothing), and it would be visible while clothed anyway, but the enemy sex animations are another matter.