This level has a nice soundtrack, but that stuck note at the end of the first loop ruins it all...
The game is getting tough from this point. So you need to be very careful to survive this level. The charger cells except the first one are traps, it's better not using them.
The only way to safely go though this level is heavily exploiting the AI of the robots.
If you make noise they will come - banging the closed blue door is enough, to lure some of them behind it.
At 2:20: In order to get the yellow key, just keep shooting the wall behind the blue door: there are enemies worth 7-8000 points that are roaming and can be lured easily, the remaining is in station mode.
So after cloaking (6:15) you can enter, and there won't be too heavy resistance. (Even that medium hulk can help to finish that supervisor robot for you...)
At 7:30 you'll need to clean the path to red door. There are many roaming enemies there, be careful. But proceed till you can eliminate that pesky driller.
At 9:14 final cleaning. From this point you should be OK.
Calmarius currently has 52,422 views spread across 150 videos for Descent. His channel published over 1 day worth of content for the game, or 33.54% of the total watchable video for Descent on Calmarius's YouTube channel.