Played until I suppressed the hyper cube. Honestly, great game. You have someting special here. I was having a lot of fun. Fel this urge to max out the entire upgrade tree, but was not able to do so, because the hyper cube was suppressed before that.
One small think is that I noticed, on some upgrades where the name is too long, it overlaps the upgrade level (the 0/3 counter for example).
Now, I'm only thinking were are you taking the game from here, to scale it. Will you make different level, with increasingly more challenging cubes? Perhapse you could make special "tiles" (wharever you call the mini cubes that make up the hyper cube) with special properties, like, can only be damaged by the drill, or the spear, etc. Some that debuff you momentarily...
Also, I grabbed a couple of stars, but I don't know what they do.
Overall, had a great fun with it. Keep it up!