Any recommendations for simple dungeon crawlers?

So, I've been interested in solo rpgs for quite a while, but it's a whole new beast for me. I've been playing various TTRPGs for the last 25 years, but every time I touch a solo game, I seem to bounce off of it.

Enter Colostle. I started playing it, and it's really fun. I'm really enjoying the story telling adventure side of it, and it's easy to play in quick bursts at work, when I'm on a break, but it's not hitting that dungeon crawler, dice rolling, scary things in the dark feel. (Colostle does have a dungeon book, but it still doesn't quite do it for me.)

So I've been thinking about it, and I realized that what I keep bouncing off of is the more complex rule sets, like Ker Nethalas as an example. I've tried that a couple of times over the last year, and once I get the character made, I get to the 3rd room, and I just feel lost... I wasn't sure why though, until my last attempt yesterday.

The rules are just to complex for me as a solo player. IF I played with a friend, I'd do a lot better, sure, and with practice, maybe I'd get better, but I have like 1 night a week where I can engage with a solo rpg, so that doesn't really do me much good.

So to my question: Does anyone have any recommendations for simpler dungeon crawl rpgs?