You should start the main character and Lucy with at least one skill. It's never good to give the player an empty skill category.
You're expected to basic attack your way through the first fights, including a boss. It's super boring. The numbers are not that bad and if you were to grant the player skills it would be balanced at least in the beginning. They don't need many, just a few. Shoot even one single skill each would be good for the beginning.
When the party's max MPs are under 100, you get an item that says it restores 500 MP, but then it restores 300 MP. I would much rather have a couple of 100 MP restoring items.
The fire boss has too much DEF. Basic attacks hit between 0 and 20 damage. I know you're supposed to beat him using water, which is how I won, but I had to use all my items. Andrey hits for 0 on it. The simple fix is to reduce it's DEF a bit.
Make the Inn free at the beginning. Why not?
It sucks that you find several gadgets, but you can only equip one per actor. I think letting the player equip two Gadgets to each actor and making an NPC that sells them would be a great idea. It's lame that the design of the game limits each character to one single skill.
Why sell the basic sword in town? The main actor starts with it, Lucy starts with it, and Andrey can't even use it. Completely pointless. Instead swap this item with an upgraded sword. (At the same price, 300).
When you find Paul, once again you have an empty skill category. Most likely you've found another gadget at this point so you can equip him that, but then he has another skill category called Magic... Completely empty. That magic skill category stays empty through the whole game. What's the point? Give him a starting skill, give all the actors a starting skill.
Guarding should give MP and HP.
Overall, I found this game to be delightfully average. Keep up the good work and you will improve over time. Thanks for participating in the jam! :)