Anyone want to play MvM UberUpgrades? If you don't know what that is, it's pretty much upgrades but totally freeform. You can upgrade your self, your weapons, and even get special tech (melee can spawn firebolts/fire spell) that uses power. There's barely any limits too.
IP is here: steam://connect/207.173.67.28:27016
Paste into your address bar.
EDIT: Huge warning: Just because you have unlimited upgrades does NOT mean this will be easy. There are severely overpowered robots that will run you down within seconds.