Added new enemy type: The Front Tanker that can only be damaged from behind or by explosions (it also blocks piercing!) (yes it's name is a little on the nose but I can't really think of a better name. If you have a better name suggestion join the discord server)

Added an outline to most sprites to make things pop out a bit more

You can no longer upgrade items you don't yet own

Fixed some bugs (I think ._.")

Did some other stuff I prob forgor ¯\_(ツ)_/¯