For new players: you can't afford to waste money on ineffective weapons. Go the dart path on both arms and something for lead in the middle. I used pineapples since they cover the whole screen. Once those are maxed, get the core active. The dart active is alright but your darts are already trashing anything but leads and MOABs.
The various badges really need to add a bonus to your score. Even just +5% blops each, I'd have some motivation to get them. Right now I'm not going to waste even 100 blops on boomerang weapons for a badge.
The lightning special gives you a chance to hit a lightning bold and go flying up, lasting longer the more enemies you hit. The rocket just launches you straight up a long way. The star lets you kill everything from any angle and is probably the best; imagine everything as a bomb.
Very cool game but upgrades need to go to higher ranks. That way those of us who suck at it can still make it to the higher levels, albeit with some grinding.
I just wish there were checkpoints or some other sign of progress between my attempts. Losing it all just takes away any interest I have in trying again.
As cool as it looks and sounds, it ends up just being another avoider and couldn't hold my interest. What's the point of cogs and experience? Have upgrades! Double jump, health regen, that sort of thing. It'd give me some motivation to keep one alive and get cogs.