I love the physics in this game, it feels really on point. Great job on that. I could definitely see this going further. I think you should consider doing more stuff with this. Get an artist on board (I feel some of the art choices were a bit off, like the bloom being too aggressive among other things) and make some more game modes or something. This could definitely work on mobile.

One thing - add some kind of penalty for using the slow down. Like some kind of stamina bar or something like that so that holding slow-mo isn't a valid option. Otherwise the entire game could might as well be slow-mo or just do without the feature completely.

Great stuff. I really liked dinking around in this!