Thanks for trying the game!
Being overpowered is expected with the current implementation of Endless Mode… I never finished the story mode, so I repurposed level 1 as an endless mode with random obstacle placement. So after 2 minutes (when the level should end), the enemy scaling just stops, and you can end up absurdly overpowered. I’ll be fixing the difficulty in endless later (probably going to rewrite the endless logic completely)… The currently limited number of upgrade also make it way too easy, since the same 4 are always displayed… this should be less an issue once I add more upgrade in the game. For the XP pickup range, the “XP magnet” is going to be an upgrade in a future version.