I found 8 of the runes and have 4 keys. Problem is when I go back to the rune placement room I seem to have lost all the runes so I cannot place them. I think it may have been after I hit the spikes? I collected more after I got hit, but still none of the runes showed up in the room to place. One other thing I did was to place what I thought were the first 3 runes in the top row of the six spaces. Maybe that caused an issue? So I'm stuck, I suppose I could start over but I want to rate more games.
There seems to be a room on the lower left that has not opened yet, maybe I missed something? I think I'm missing a rune for sure as I'm guessing there are 9 but I only found 8. It must have blended in a bit too much with the background or other tiles.
FWIW I really enjoyed the game, fun interesting puzzles, didn't care too much for the spikes as part of the game, but I can see you wanted to add some variety I suppose. Great sound, don't recall all the sounds if any as the music, while amazing, was a bit too loud. LOL Visuals were all great, it would make a fun GB game for sure, so definitely Gameboy Soul points there.