Hi! New ideas have come up during the break since the particles implementation. Sometimes it’s a good thing to take a break and come back with fresh new eyes 
I decided to create ten levels, with progressive difficulty. Here is a sketch about it:
I tried to create an epithetial tissue environment (if you want to know more about this topic, Wikipedia is our common friend: Epithelium - Wikipedia). Each part of the environment has its own material:
- red for friendly cells
- green for infected ones
- glowing green for the target, the cell to cure
Here is a screenshot of the fourth level, for now:
And with the movement, it might be easier to understand 
The game design is still very simple but I started to use some “learning tricks”. At the first level, there is no infected cell under the character, so you can learn the first mechanic (use gravity and move) without being injured. At the third level, this part of the environment is infected so now you have to react faster or fail 
I still need to fix the issue with particles and SFX continuing to play after the level ends but I’m quite happy with the actual result
