I was.....(pardon the pun) blown away
None offense meant, but this reminded me of one of those live action games on the CD-i, except this is way better than anything that hunk of junk put out. However, I do have a couple tips for the sequel.
1. Those pop-up boxes are annoying. Not telling me to shoot the gargoyles or that that guy can dodge head shots would have made the pacing way better and raised the fun by allowing me to figure things out myself.
2. It's WAY too short, and WAY too easy. I really would have appreciated one more level, or at least not making the first so small. On that note, you could put a shop in-between levels where you could spend money earned for defeating enemies. Here, you could buy health, new guns that you could switch between, and even power-ups that you activate any time by pressing a key. Yes, I realize the pains of stop-motion, but if you really want to knock my socks off, you gotta grin and bear it, k?
3. The sound is alright, but it could have been better. You could have changed the tune during the boss fight, and the main theme got just a bit repetitive. The sound effects were good, but I started to notice the little things, like: "Why didn't it sound like I was shooting wood when I hit the barrel?" "Why don't the gargoyles make metallic sounds when I shoot them?"
4. For a rail shooter, the whole experience felt kind of slow. Again, this goes back to the constant pop-ups, as I don't need you to tell me I can shoot down that barrel, but it also relates to the enemies. First off, they're too slow. It takes each one about two seconds to walk on-screen, and I can't kill them while they're walking. That really confused me on the first enemy, and I ended up wasting ammo early. Make some foes drop in unexpectedly, or have a foe that moves around. It also doesn't help that the main character walks at half the speed of smell through the whole level.
I applaud you for making something this good for your first submission, and it's by far one of the best things I've seen today. However, take my advice and you'll see killego 2 appearing on some far more prominent lists; maybe even the "best ever" one.