My claw keeps falling off... 
Also, I've been shot by corpses on occasion and sometimes I'll just randomly phase through objects.
Oh yeah, and random big dark rectangles will sometimes flash on the screen for a split second. 
  
/rant

My boinic man kept shouting after a slam as if he was falling infinitely.
Also, the drones seem to attack randomly. Sometimes they won't attack an enemy right in front of me.

I ended up getting stuck in the death from above animation and just slid along the ground until I found a pit.
All the time, Spencer is screaming his head off.

Found a few new ones. 
Spencer landed on water and behaved as if he were on solid ground, although I still lost a life and the game respawned me a few seconds later. 
I was able to grapple onto the air next to an elevator. 
Shot and killed a guy with my pistol, then watched as he ragdolled and flew directly at the camera at approx. 300 MPH. 
On countdown, immediately go to the right and jump into the water to the right of the extra life. You will spaz out and ragdoll on top of the water every single time. 
On some levels, hacking terminals will not disable all the turrets that they are supposed to. 
Grappled to a barrel and fell through the level when I reeled in. 
In co-op, when in menus you will lose most thumbstick control (at least as the first player). 
In co-op, the first player's item setup will sometimes overwrite the second person's randomly.

The only bug I really noticed involves the Death from Above move. For some reason, if you do the move and right before landing near the corner of any edge while pressing the analog stick to the left or right, the scream sound will just loop infinitely. It's kind of funny at first because you keep hearing a mustachioed man screaming. You can just make it stop by doing another Death from Above though. Still, that really ticks me off more than anything.
 
Not every dev put effort to these littles details like GRIN I guess (RIP by the way)...! 
 
*EDIT: Oh yeah, I also noticed when you want to grapple onto the edge of some platform using the advanced grapple move (while falling, press down on the analog stick + B), you'll sometimes teleport to that edge at the speed of light. Hopefully they'll release a patch that fixes all these littles non game breaking bugs.