Thanks!
It was definitely inspired a bit by Alien Soldier, heh. Probably some subconscious Mega Man inspiration as well with how much I like the Mega Man series.
Also, there isn't anything for beating the secret boss, but if/when we do an expanded version, we might add something for it. The reason DIE5 doesn't work for everyone is because it requires holding more keys than some keyboards like having held down at once, which is why the other options are there to begin with, haha.