Ive unlocked everything yesterday and I think some new Sidearms could be some fun maybe a sidearm that lets you carry two guns and both get upgraded when you enhance, or one that could let you see the HP and Ammo of the opponent so you know when they are going to reload so you can ambush them easier (I found that waiting till they reload so I can Mag dump on them sped up a lot of kills), maybe one thats a sword that lets you dash forward like the boss from purifier, This is a great Rougelike Third Person Shooter, maybe a shop system at the end of certain depth which use the points you have gathered will grant a use in game (Extra upgrades dor deeper runs) like getting a mote powerful gun or a cool Sideweapon, perhaps Ive noticed you rack up points quick and once you bought everything they become useless and this would give a gameplay reason other than the main menu shop :)
I cant wait to see it and you Evolve!