Brilliant idea, really well executed. You had a good amount of polish too, considering it was a game jam. You could definitely take this further with more enemy and level variety.
I have two minor gripes with the design that I think you could tackle to improve:
- I found the optimal strategy was to stay in the middle of the level the entire time. I think this is a HUGE missed opportunity. I loved that you had to avoid the big bars / lasers that show up across the screen and so you have to avoid going to those areas in all your selves in order to be sure, but this makes it so that staying in the middle is optimal. I don't know what the solution is here, unfortunately. I would have liked more level variety.
- I found it really punishing to have to replay parts of the game specifically because of how long each round is (or feels). You can reasonably expect new players to have to retry the game a couple of times, either from the start or from a specific round. 30 seconds doesn't seem like a long time at first glance, but those retries stackup. I think retries should be a shorter duration, but maybe amp up the action a bit to make it still challenging. I ended up retrying 5-6 times, then I got to round 10 and the original got hit (already happened to me before as well) so I decided to stop. The game is very fun but if you keep retrying, it can get tedious, and you want to stop because you get the gist of the game at that point.
I did really enjoy the game and the concept, despite the criticisms, I hope you can keep improving it!