First off, I absolutely adore the pun. Hell deep is your love/how deep is your love, top notch.
I also adore the visuals, and the music. They work in tandem together and are great. Love the bopping little animation our character does to the music and the colour palette you chose for the game. Great stuff.
Also great use of the theme, that auto scrolling, always going down (for most of it) was always daunting and stressful but in an important way.
The only problem I had with the game is with the movement and level design. For what the levels were asking of me, my character just felt a bit too big and not very tight enough to maneuver out of the way of the obstacles. I think whilst most obstacles were well placed, some times it just didn't really feel right. On one of the levels at the very end, there was no indication I needed to go between two walls, because there was a huge gap to the left as well, and I also fell out of the game on the right I think, but this was quite minor.
I had to quit on the, I think?, last level with the flying bat that shoot webby slow sticky stuff. The rope mechanics and also ladder mechanics did not feel as tight as the general movement. When I stood on ladders the fact I fell through instantly also didn't feel good. I think perhaps if you stand on a ladder you should just stand and then press down to climb down.
But great job overall, you mad a solid game that with some more work and polish I can easily see being a great challenging platformer for any hell bound masochist out there, especially with those tunes! Great job to you and your team!