I can only report Empire Mothership II prison sequence not working as intended (you can't kick the barrel, but you can activate the switch through the wall)
But this is not what I'm here for. I've just beat E5L1 (the cube level). Motherfucker.
Here's the best of a guide I have for beating this level. There are SOME inaccuracies (i have no idea how I got in exactly one area), but this is the best this fucking level will EVER get.
Spoiler