Not great...

...But don't give up! You might suck today, but you'll rock another day! Keep trying and brush up on flash skills.

what happened to the end?

Sonic, Metasonic, and Shadow just disappeared but the song kept going. Yeah, I couldnt read the words - they disappeared too quickly. Keep up the practice

ehhh

animation choppy needs work. u need more plot. and u need some practicing on ur spriting and animation. try not to make the sprites feel like paper by flipping them aroun. if u need to have htem rotate customl make them rotating. alsoi noticed some of ur things were compressed tot he point hwere htey have grey around them (mostly ur bgs) in the library right click options set it to png and gif compression. should fix all problems with bitmaps

Eum....

Plus Side:
-Yay! Metal Slug dude!!!
-Soundtrack O.K
Minus Side:
-Mediocre Animation and Spriting.

This Flash is pretty basic.

The sprite animation is decent, but it could use some work. Try to make it look smoother and more natural.

You put in voice acting without subtitles, as well as putting in text dialogue. This inconsistency is annoying. Shadow's voice was too quiet. Also, the dialogue was often hard to read against the background, and scrolled by too quickly in some cases; you should put the dialogue inside a speech bubble or some other sort of background to make it easier to read, as well as adding a button that the viewer can use to move to the next section of dialogue, so that we can read at our own pace.

The plot. It was difficult to understand. It needs better presentation. Also, from what I could tell, the plot itself was pretty bland. It would be helpful to rethink it a bit.

Sound effects. You should put in more of those. They add a lot to a flash.