Thanks for the feedback!
The difficulty is dependent on the different colors, if you stay on the blue ones there is 25 levels (that gradually increase in difficulty) to complete placed in a 5x5 pattern where you start in the middle, and you will get most upgrades before moving onto harder ones if you just complete some of them. I did plan on making a minimap to show this (the level layout) so the player knows when he leaves the blue area this but never had the time to implement it. The originals have same mechanics with harder levels further from start but they state that fact in the tutorial which I should have done as well I think.
Also it was meant to be a rampup in difficulty for the player when entering areas with new colors so that if they were to weak they would realize they moved onto the harder level to early and go back for some easier ones to build up power.
Also atm the acquired powerups will never be lost even when losing bubbles, but the ship will degrade. Will prob implement losing powerups later on.
For the controls I seem to have made an error at the acceleration phase making it faster to acc diagonally, but the max velocity is same in all directions.