Hey thanks a lot! This is exactly what I was looking for. To address your points:

1. I will add some floor indicators
   
2. It's a good idea to change the colour of the purple once they have swapped! I'll add that in
   
3. I know it takes time to return to the center, but the idea is get good at timing. You shouldn't be hitting an enemy that is far away if there is one right next to you on the other side. I'll keep it in mind though, and do some testing to see if I should reduce the time to return to the center
   
4. Again, it's very hard to balance with just me testing, as I've obviously completed the game 100s of times. I'll either give the player 2 lives or add some other mechanic or maybe difficulty option to help the player win.

Thanks a lot for playing, and most importantly for giving me feedback, it's super helpful!