I didn't find this level as bad as other walkthroughs may suggest. But this level is still tricky indeed.
You must be fast to get to the second floor before the mechs there go wandering.
But don't slow down: clean the second floor, destroying the green platformers is the most important task.
The area beyond the yellow is the hardest. You must stand here and lure the bots and destroy them. The red hulk rarely go wandering so you can surprise it with a smart missile.
Before entering the red room make sure the exit is clear: green platformers and small hulks tend to collect there, be careful.
The reactor room is not too hard, but there are 2 red hulks can surprise you down there. Make sure to use any missiles you can find.
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.