For somebody who is new to game dev, this is a solid entry, so congratulations =) ! You'll become better and better with every jam, don't worry about that ^^.
If you don't mind, here are a couple of small things that adds a lot of quality to your games for a minimal time invested, for the next jams ^^ :
- Improve your gameloop. Here, the mana doesn't refill enough, even if the ghost doesn't touch the player, and at some point, the level is filled with skeletons before you have enough mana to shoot. In general, ensure that the player can progress in your gameloop ^^.
- Sounds =p ! Sounds are an easy, but huge improvement to your game ^^. Look for "Audiosource" in Unity : just add one in your scene and bawm, sound. Here, having a little musical theme and a sound everytime you shoot.
- Controls : I use a AZERTY layout, so I have to switch my layout to play. Also, the arrow keys doesn't work, even if you say so in the menu ^^. Maybe check Unity's InputSystem to make your game compatible with all the layouts, and being able to add new bidings easily ^^.
These are just some little advices about what to focus on for the next jams, but it's still a good attempt for a beginner. Congratulations, you can be proud =) !