Again, thanks for the detailed comments!

Would be cool if you'd write a review afterwards.
I'm glad you mentioned the vertical progression in map 6, that's the thing I like the most about it.

. There seems to be a cutscene that doesn't work at the very beginning of the map though, there's a quick screen of another angle of the room that lasts for half a second then it says 'checkpoint reached' straight away and the action starts. The same thing happens again and again upon reloading. Not sure if that's supposed to be normal
There's no cutscene, you just wake up in the alien cage from the old x64-2 map, and the commander shows up pretty fast. I think the checkpoint system just gave you a little game freeze, it happens sometimes.