Just want to offer some assistance in the form of written and video help found on the internet. There's a normal puzzle to get to the gate, which will earn you
Then there's a real-time Boss battle that totally ramps up the difficulty and frustrates many players, including me.
Neoseeker.com has a good walkthrough for this game. Here is their page for this chapter:
https://www.neoseeker.com/helltaker/walkthrough/Chapter_IX_-...And here's a full 100% video from ButtonBashBros on YouTube
Timestamps:
Level 1: 00:37
Level 2: 01:17
Level 3: 01:48
Level 4: 02:21
Level 5: 03:02
Level 6: 03:32
Level 7: 04:17
Level 8: 05:03
Level 9: 05:41
Final boss stage 1: 06:41
Final boss stage 2: 07:42
Final boss stage 3: 08:37
Final boss stage 4: 09:55
Ending: 11:35
Secret Ending: 15:44