Didn't have any time to work on this during the weekend but today i'm back! I added UI elements so that the player can see how many of each crystal they have and also implemented fireballs that the player can shoot using their collected red crystals!
Shooting:
Besides this, I've been thinking about what to make of this game. I'm leaving for a small vacation on Thursday and won't be able to work more on the game after that. So my plan is to implement a few more room templates for the level generation, add "spikes" that the player must navigate around and finally add a simple boss at the end of the game. The player will have to collect 10 blue crystals around the map in order to unlock the boss room and fight the boss. I've never implemented a boss fight, so it will be a fun challenge.