I will give you solid 4 and try to explain myself. It might be a rather lengthy post.
First - it was surprisingly enjoyable considering a bunch of things that could be better and small bugs (sadly, not butterflies). I really like the fact that you put effort into creating different paths in story or even small side quests, they were natural and because of the choices I will replay this game for sure.
Now, about things that are mostly connected to how you made game (engine):
1) Everyone brings out animations in battles and this is certainly the weakest point of the game. There are delays between turns of combat, animations of melee attacks takes a lot of time as you made everyone walk rather slowly to enemy and back again. Pity you can't change it now as stated in some response, it would make this game so much more enjoyable.
2) Issues with mana. I had April-May at 7/10 for most of the lighthouse because she wasn't gaining anything more. My main hero also was stuck at 14/15 at some point but during different battle I was able to get 16/15 because of recharge at the start of my turn.
3) Combat system i.e. skills bound to keys is a very arcade-like system and rather pointless in slow paced RPG game. I also had problems with cancelling once selected action - is it even possible? And exiting battle by Esc doesn't require confirmation, a bit harsh in lighthouse when I wanted to try to get it done faster.
There is one thing I want to suggest you - try using RPG Maker or things similar to this. There is a lot of games that are made in it and you can rather freely operate within it and you are going to have a lot of things done for you (in terms of underlying mechanics of engine). You should check hentai game "Noxian Nights" - if you don't know it, it might be very interesting for you to see how a lot of things can be resolved. Of course, battle system in that game might not fit your preferences but it's just one way of doing it (you would probably prefer combat system from "Mardek RPG" series).
Just by creating same game using different engine you would get rid of several problems this game has. I can understand that you might want to improve your skills by doing everything from the scratch and it's surely fine but I would suggest using existing solutions first and if they are not satisfying - then creating new things. This way you will learn a bit different things but you will get more things done and they will have higher quality. It's up to you in the end but if you are studying programming as you said somewhere you should know importance of using good libraries and not developing everything from the scratch.
Just two bugs I found:
1) Mana issues I pointed out above.
2) When I climbed tower first I didn't encounter a mage. For some reason I could trigger dialogue with girls and sex but had to climb it again to fight mage and light fire. It was painful
And now, in the last part, a few things about balance and design decisions.
1) You made monsters auto-scale to hero's level which kinda makes levelling a bit pointless, or rather a bit more painful. When I played I didn't know how to get quickly teammates so I was just trying to farm enough coins for gear and then advance. It made my hero quite powerful compared to later received companions and monsters were powerful enough to take them down quickly. Monster scaling is a tricky subject and I have to admit I rather prefer either combination of scaling and zone limits (for example starting zone will scale monster levels up to level 5 of hero and so on).
2) Mana system made fights long and boring for me. When I entered lighthouse I couldn't simply escape battles and had to fight everything. So basically whatever I was fighting I had to kill ranged attackers first (as they could k.o. my girls and were inclined to attack them) and then spend several turns recovering mana to be ready for next fight. I guess I should play on easy difficulty to cut playtime by 50% - and 50% cut would be just idle sitting and pushing buttons for recovery, nothing interesting. Again, if you don't know how to nicely balance it - maybe use system from other game. Using tested systems isn't a bad thing as you have different things as a main dish in your game.
3) Potions/items being automatically used. I think I should put this to previous section but it might be a design choice (even though I think it was just a limitation of combat system). I don't really like idea of having my consumables taken from me automatically, it takes away crucial planning especially for long dungeons like lighthouse. In the end I just had a bunch of herbs saved for my hero as everything else had to be used automatically on pointless battles.
My review might look rather harsh but I wanted to point out things that made, have to say it, a bit mad - because I know that had you created this game in a bit different way it would be so much better. I don't regret spending time with it and writing this review, I will certainly revisit it after you will deal with some small problems you have now. And I guess I will play it on easy to just be able to freely go through battles without mana problems.
In overall, a nice game. I really want to see your future works done in some tested engine so you can focus on content, not on engine problems.
PS: I don't remember anything else that I wanted to point out in review, I guess I will PM you in the future if I find something else.