Army of Two: Devil's Cartel - Out of Bounds in Chapter 31
3Just found this by accident yesterday. At Chapter 31 there's a part where you have to give cover fire to your pals at street level. But you can use a small floor to walk over a railing blocking you and get to the street level early.
Since you meet your pals early, there is no cutscene trigger which would end the Chapter here. The extra invisible walls that would block you from all directions are not here either, allowing you to go fully out of bounds.
Aside general sightseeing, another interesting thing this OoB has to offer is a glitchy vehicle that you can drive around a bit. On my first test it was in-bounds near the manhole cover, on second attempt it was beyond the rubble (but you can reach there by going via OoB, as shown in the last clip).
The invisible vehicle will pass through all collision on the way. You can steer it a bit, but cannot reverse, and the exit button is not "Square" as the screen prompt shows - rather, it's triangle for some reason. Your character can't die falling out of bounds in a vehicle, he just gets stuck in air. But exiting the car proves very fatal. Perhaps the bottom of the map has crushing ambient pressure, much like the bottom of an ocean has.
Another thing - the invisible vehicle seemingly once you've driven it off the map, and retries won't bring it back. So to drive it again you have to restart the whole Chapter, it seems.
Would be nice if this could be used as a speed tactic, but at least solo it seems very unlikely. The final cutscene trigger of the Chapter won't activate until you've killed all the enemies, and using this shortcut just takes you further from the enemies. Perhaps it might still save a bit of time in co-op?