Descent - Insane-max - No Damage - Level 18

Hello, I was experimenting with new challenge, where the idea is not loosing a single shield during the level, not even by contact with walls. Really difficult I would say. And I'm not sure if all levels are technically possible at all... 18 is overally not that hard level, but roaming brown hulks in narrow corridor at the end are a pain. By far the worst spot and you have to face it after doing everything.. The other problem is yellow key area, roaming drillers make it based on luck, also four drillers after taking yellow key are tricky. Especially two upstairs like to move like crazy, randomly shooting and bumping in your face even when you are cloaked. Somehow they "smell" you... That little step back at 2:46 is to trigger matcen. Since I need clear that matcen and don't want boringly farm it, I trigger it in advance and later I can clear it in fast fashion. Played in D1X-Rebirth 0.58.1 with keyboard only.