Things to Improve (still a good game however)

1. MAIN MENU SOUNDS: They are annoying to hear and they're all the same! If this one sound is absolutely the ONLY option you have then at least set it to play at different random frequencies every time.

2. PUZZLE MUSIC: A lot to say bout this. What you have is umm ...alright... ehh, well actually just tolerable... and that's really just cuz it only lasts a short 12 Seconds and on top of that you have it looped continuously on end. You seem to have got the genre, style 'n ambiant vibe for a simple puzzle game all right. That's Good! However NO ONE is going to want to play a relaxing puzzle game while feeling annoyed. There are Multiple things u could do to improve this: A) Longer Song and DON'T loop it end to end! Leave space between plays and make sure the music fades into these pauses and Not drop of imediately B) more songs. Preferably calm and smooth stuff like the one you got now. Nothin too dark, lighthearted, or exciting.
3. ALL SOUNDS BADLY NEED REVERB: Ya know... a small echo feeling. All good music out there has at least some sorta echo/reverberating of sound. Even when you think you don't notice anything it's there! With out it, every sound in this game sounds earbleedingly sharp, piercing, unnatural and obnoxious even with the volume very low! Plus everything just sounds awfully loud too!
4. NEEDS MORE: The game Should have more puzzles and levels than just one, as can be imagined! Any picture will do of coarse but an attractive girl pic IS always a nice way to grab attention, So what you have already is good! You'll just need more of it now. Oh and undead chicks... umm... it's not really everybody's thing, including myself. Most ppl would probably be turned away by it just sayin. But I also see how this game fits in with the black cross thing it's part of.
Hope this was all helpful to you!