Fun mechanics! Moving around quickly and smoothly. One strategy I found, I liked building up trash pieces to big amounts as backups if I couldn't plug up a 1m or 2m black hole or find enough pieces to plug it up in time. I'd suggest moving the Black Hole Collapse Timer to the left / near the Hyperspace Requirement increment. That way, I'd only have to look in one spot to have both information. I had been ready to plug a 8m hole with a 10m pile, but then I lost on time.

Other things I noticed: Jumping on the platforms was a bit wonky. couldn't always get up the next step easily. Had to step back a bit and focus on jumping, which lost me some time. 
Also, it's not super intuitive that when you are holding a yellow junk pile, you can't combine objects to it. I was able to pull objects towards me, but it would not stick to the pile.

*Possibly, you could color it red as you try to pull to indicate that it cannot be combined? Or, make it so it does combine.

In the beginning rounds, 1-10, it felt a bit easy as I was able to easily plug up 1m black holes. So I spent my time collecting trash to build up multiple yellow hyperspace piles. However, I did notice the difficulty later as it the blackholes were increasing faster.

Maybe new levels / some better movement / different types of black holes / key objects may make a hyperspace behave differently?

Really fun game! I really enjoyed it!

Good job with what you've all made in it!

The gameplay loop feels like it needs to be readjusted, you all clearly have the skills otherwise in your respective fields. Adjusting the gameplay a bit, and the game will be great!