Dungeon adventure and writing assembler in DOS are incompatible you say? No, they’re not. And also you need a lesson in assembly. Luckily for you, there’s a game that perfectly suits your needs.
Start the first level by command `START 0`.
Side note 1: Yes, I know this is the game that nobody asked for, but trust me, I suffered more when I had to write it than you will when you’ll have to solve something using assembler.
Side note 2: Normally, this would be considered cheating, but hey, I know some puzzles are not easy and that I flunked the tutorial part. Here are solutions to all 13 layers.
Tools: Phaser as framework, GIMP for sprites, “music” by fiddling with WolframTones.
A game made for LD41.