Merry Christmas

First off, I have to say that this piece is very nicely shaded, and for most part the proportions are well-done. Classic Sonic in particular is very nearly on model, and Modern Sonic is not far off. The text is nice and the colors surrounding it are very well-chosen.

There are, however, a few problems with the piece. The most notable is the absence of Modern Sonic's left arm above the elbow, and the strange angle at which his eyes are situated. The sclera of the eye is fine, but the iris and pupil are tilted at an angle that does not match the angle of his head. The piece could benefit from something suggesting more spines on his back, but it isn't really hurt by their absence either. The layering of both hedgehog's hats are also not what I would expect; are they supposed to cover their ears?

Classic Sonic is much better composed, though the top of his head seems wider than the bottom.

I find modern Sonic's hand pretty interesting. One hand, it's clearly not the most polished aspect of the piece. On the other, it doesn't stand out as being strange or off the way many other fan piece's hands do. The proportions of it are perfect relative to Sonic's head, body, and arm; it's just a bit too wide for the placement of his thumb.

Classic Sonic's visible hand is perfect. I'm impressed.

If I were to make suggestions for how to improve the above stated issues, I would suggest the use of guidelines. You can also take canon pictures of Sonic and draw lines on them between the eyes and nose to help figure out where eyes should be placed when his head is at certain angles. I would also look at pictures of fuzzy animals with ears on top of their head wearing hats to figure out whether having the lip of a Santa hat over Sonic's ears is appropriate, and make the effect more dramatic if it is supposed to be that way or put the lip of the hat behind the ears if it's not.

As for the emotional content of the piece, Sonic's character is dead-on, the background is somewhat interesting and and more dynamic than you'd expect of something like this, and the choice of font leads to plenty of cheer. For a piece by someone in a country that doesn't celebrate Christmas, this is pretty darn festive!

Thank you for creating such a cheerful piece, and for opening it up to critique.