Short, senseless, but well-done.

First of all, this movie contains only one fighting scene between an unnamed hero and an unnamed demon villain.
Except for this fight, held in some dark red field, there is nothing.

The animation is well done, the artwork itself is pretty good. Also, the soundtrack, although badly balanced, contributes well to the scenery. Still, the flash has about zero story and although being tuned to be stylish, has absolutely nothing to offer. 6/10 points.

-1 point for giving a wrong age limit. This surely isn't suitable for all audiences.

Not original at all.

This is not original in any way. We've seen hamsters, frogs, George W. Bushs - all kind of different objects or persons tortured interactively. It's just not orginal anymore. This flash has absolutely nothing to offer. A smiley killed in different ways - even the graphics aren't that much of a deal.
I don't really think this is in any way a flash that people have to see.

Nice arrangement, awful guitars.

Please, why is everybody using these malicious Slayer-VST-FL-Studio-guitars? If you ever listened to rock music you would notice that they do NOT in any way sound like real guitars but like synthesizer bullshit. No offense.

The arrangement and composition is okay - up to a certain point, not superb, but okay. The drums are a bit monotonous, a bit variation would be helpful.

The song quality really decreases rapidly at 01:46. Instead of variating your song with new riffs or melodies, you keep adding really cheaply sounding synthesizers - they seep completely out of place in a song which is supposed to sound like rock. This can especially be seen at 03:16 when this really cheap Sytrus preset lead synthesizer plays alone. Use something more quiet and delightful here, a piano, perhaps a clean guitar or harp - but not these awfully cheap VST presets.

Variation and better instrumentation are the keywords here. The song isn't bad, just not good executed. You have the talent to do so, so search for some guitar players and keep rocking :)

Okay composition, bad instrument quality

I seriously can't see how thing song is able to get that high a scoring here. It sure as hell isn't a bad composition, I find the song itself only to be completely ruined by it's way too artificial instruments.

First of all, the composition may be not bad, but it's certainly not good. There is little rhythmic variance, the guitar almost plays (with exceptions) notes with the same duration - and the monotonous drum scheme only contributes to that. There a little to no surprises, the listener knows exactly what to expect.

The next point is the lack of other instruments. Of course, this song is called Guitar vs. Piano - and you have these two lead instruments in the foreground. But a simple bass instrument would have helped a lot. Right now it sounds like two instruments playing somewhat random notes without structure.

Let's get to the main point of criticism. What ruins the song for me is the guitar. As a guitar player, the sound hurts my ears. It's just that no matter how much effort you put in it, you can't simulate or sample a guitar. Abandon all your software samplers, vst instruments or plugins when it comes to electric guitars and get yourself a good guitar player. There are enough. Nothing can make a song sound bad like an artificial guitar - and especially that Slayer thing which comes with Fruity Loops. Also, the way it's played is very uncommon for a guitar, it does sound like some techno-ish / chiptune music to me, not necessarily something that would fit to a guitar.

The piano quality is okay, it suits this song well, way too much reverb for a 'normal' piano - but right here, it works.

What could you do to improve the song?
It's quite simple: Redo the song, this time add some structure to it. Add some variation to the drum scheme. It lacks overall depth, think about better samples here. Write the guitar line so that it fits with an actual instrument - and search someone to play it for you.

I don't mean to offend you, you're not a bad musician, certainly not. But you definately have to make your music sound less artificial and add a human touch for it. Or make 'real' electronic music, which also works. But don't cross borders here.

Keep it up :).