I love the look of the physics simulation as the cubes pool up into a ball. I don't know why exactly, but it gave me Control vibes with the powers in that game. It makes for a solid base puzzle mechanic.
I think there's some optimization issues with that simulation as it was difficult to have high input latency because of the complexity of these simulations. I have a pretty capable computer, but it struggles once a decent number of cubes were spawned. It was also frustrating that the esc key closed the game as I was expecting to get a pause menu to check the settings/lower the resolution so it could run better.
Overall, I think it's a really cool concept that follows the theme and the wildcards really well!
It's also worth noting that you should ensure that you have some kind of total spawn cap for an entity as you can spam the cube spawn and crash the game pretty quickly as well.