Drones....No way to use them or there isn't a note of "Do X to use them." So skill points spent into that are worthless.
No way to respec, if a mission is basically impossible for you to pass, the weapon upgrades are terrible, the damage upgrades are worse. I'm 4/5 damage upgrade weapon 3, i'm failing to kill things on boss 3's mission that shouldn't be happening at being 90% maxed in power.
The horizontal and vertical blasts of freaking no where don't help either, your power scale of a hero compiled with the fact enemies blast everything while you are now being hit by random lines of bullets at which point become impossible to dodge.
Over all got annoying and thus bored really fast, needs to be balanced a lot better or skills need to go to higher levels or something, the progression of you vs enemies is you crap them great.