Ya know...I almost ragequit the first time the nightmare beat me and I had to start over. I stuck with it and actually found this to be a great game.
The game was very original and I loved playing it. There's something I like about gaining levels just for standing around and I'm a sucker for 16-bit sprites. Level design was great. Some of the things you had to do to achieve skills were very difficult, but I like the fact that you allowed me to be a pansy and just buy those abilities.
The technical issues kept me from voting 10 on this one. The invisibility bug didn't kick in until around day 7 but by then the nightmare was almost too easy to beat. I'm not sure, since I was invisible the whole time, but it seems that the dash ability can make you invulnerable throughout almost the entire fight. Just dash into one wall and then dash into the other. Rinse and repeat until you've collected all of the gems.
Also, I refreshed the screen at one point in attempt to try to cure the invisibility glitch and I may have noticed a couple of more bugs. The waterspouts no longer worked but, when I went to the lever, it acted like I had already pulled it. Also, are you supposed to have to pay 100 gems to open the door again?
Another weird one came after I got your reward for 100% completion. After it sent me to the start screen, I went back into the game to get it again and I was unable to interact with any gems. They just hung there while I walked right on through them. I was however able to collect the gems I needed to get back to 100%.
Speaking of the 100% completion reward...very nice. I look forward to the next game. :)