To save people time:
They are both based off the same characters, so yes they are going to look similar. Why don't you actually examine the two artworks side by side before jumping to conclusions? There's two things that are similar about our artwork. They are Castle Crashers and they are pixel art. That's it. There's not a single pixel in the same spot on the characters. The helmets, bodies, shields, colors, shading, are all different. Mine have no weapons (because I was going to make an animation, so I needed empty hands for exchanging weapons). Yours do have weapons. Mine have actual crosses on the tabard, yours do not. My face mask points align with the point in the masks, yours do not. My armor and ear compartments are rounded and bulging, almost puffy, They aren't even the same scale. So there's no way that this is stolen, or copied from your work, as there are far too many differences for it to be even plausible.
I have two Castle Crashers animations dated a year before your fan art (which is dated a year before these were submitted, yes, which is also coincidentally a year ago.) I draw Castle Crashers all the time, as it's one of my favorite games to play. None of these things are truly our own, original ideas, as they are ALL based off of the artwork of Synj (Dan Paladin). And surely, you can admit that your pixel artwork, couldn't possibly be the first pixel artwork of the Castle Crashers characters, as they were posted a whole year after the game came out.
For what its worth though, I do like yours better. And I've looked at some of your other artwork too, and it's really nice. You should consider submitting it here.
I'm not bitter, I just don't want you to feel slighted. Thanks!