i'm a big rpg fan so thats where it comes from haha, I was thinking about adding stats as well that you can add when leveling up but ended up not doing that because there was not enough time to balance it all (as the game is already very unbalanced)
the shop is in the main menu (outside the game right before you click 'play')
yes i agree it needs a lot of tweaks here and there to make it a real challenging game that can be fun for more than 5 minutes :)
thanks a lot for your valuable feedback!