Ok, first of all, I hope any and all efforts towards continuing and developing this game are ongoing, because I want to play more of this!
I'll start with the positives. I LOVE the graphics and the artwork. The background reminds me of a black metal album, and it genuinely is gorgeous. I like how the little savior sheep is outlined in blue to differentiate him from the other sheep. I like how when the level is completed the little rainbow appears. It is a nice contrast to the darkness of the overall game. I love the music: the disjointed chanting when you win the level is really pretty. I generally also like the sound effects, such as the horn at the beginning. That, combined with the artwork, really set the stage and made me believe an animal sacrifice had taken place.
Now, for the negatives: While I liked the blue outline of the savior sheep, I didn't like the red outline around the platforms. I think the intention might have been for them to look "hellish", which I understand, but I just think it looks kind of garish in comparison.
The concept of using up lives is an interesting gameplay device. The player has to strategize in order to pass the level. The fact remains, however, that you are still losing lives. It took me a while to get through the level, because I didn't necessarily see where the platform ended up, because I had died by that point.
Like I said, I loved the music and the sound effects, generally. The screaming throughout the game got kind of old though. If I lost the level, the howl at the end seemed to take forever to stop. A short 1-2 second menacing piece of music (like an oboe or something) would suffice and let the player know that he/she "lost".
The mechanics were shaky. Sometimes, I would slip off of a platform. If I wanted to jump towards one of the crosses, I would have to go right to the edge of the platform to get a good jump. I don't know if the next thing I'm about to mention was my problem (I'm playing in Google Chrome), but when I would use the arrows to move, it would move the game screen with it. That can be a bit disorienting.
At any rate, PLEASE continue improving and developing this game. You only gave us one level, but it was visually stunning, with beautiful music, and a creative story. We need more little platformers like this. I will be angry if I don't get to play a full version!