Great idea, although it is used by a lot of people. the problem is I could only watch one slime and beat the levels. Meaning the second slime does not matter. the levels have to be asymmetrical to make both slimes matter or use a mechanic that requires the slimes to be in different places from each-other. In your case the former makes sense. maybe make the levels start symmetrical, but slowly get off from each-other. I rated the theme lower because of the slimes not actually needing each-other. Besides that the game could use some polishing. I will like to see this game in the future.