The upgrades arent doing anything, all the debris spent on the blue shield does nothing when it just becomes a level 1 shield past the 10-15 second mark, might as well not bother with anything.

I have quests that i cant complete anymore because im too far down the skill tree and it's counter productive to the objectives.

The Challenges arent so much as challenges as more of a test of luck to see if your upgrade path is the one the dev wanted you to have when completing said challenges (which as mentioned before, if you chose to upgrade your shield you are shit outta luck)

Metaupgrades dont offer any meaningful difference, just a "here have a miniscule number buff/debuff to what you are already currently doing with your regular upgrades" Especially the "debris loop around the screen" upgrade is more of a detriment. you'll ahve random debris scattered across the screen with no way of actually ever being able to grab them, they are just there, and im willing to bet that lower end PC will struggle with this.

Also as others have pointed out, the cost increase is astronomical. you cant expect people to do 190 second rounds 3 times just for 1 upgrade when the gameplay doesnt change in anyway.

Im also going to assume that since this is the demo, another colour shield will be available. instead of having them be on fixed positions and having to choose between which colour debris you want to farm at that point, make it so that you can swap between shield colours, that way your skill determines what you can block or not, not some arbitrary rng of what two blocks will be coming at you at different angles.