It took me a little to understand what I had to do but when i got it, it was fun^^
I don't know what Old Grumpy is or what he is attacking with (his mustache? his breath?) but I like him. Loved his expression before the boss fight.
The description states that this game was a demo for procedural generated dungeons on GBStudio. i don't know on what extent that worked, but I recognised that the rooms didn't always had the same enemies. Luckily for me the room has the key after it had it for the first time. I saw it too late on the first time^^"
Interesting game, I like it.