Nice! Very cute creatures!

It's none of my business, but what if the Moon turn the other way? Right now Moon looks beyond the frame and obviously she does not care about the characters. Just a suggestion. 

Yep! Glad someone noticed (: 

The character design reminds me of "Cave Story." Inspiration?

 Cool, a review.

I've tried and failed many times to apply anti-aliasing, and so i've grown attached to dirty, tough-cut round shapes when I'm pixelling stuff.

The light-ish blue things are just part of the logo.

Not sure of what to say about the tiles :I

I've always been a sucker for clean and minimalistic pieces. But I do feel like some anti-alias is called for in this one, though, specially around the moon, but overall in the round shapes of the background.

You have a nice selection of blue shades there, you should put them to better use, like softening the edges fo the background shapes, for example, or diversifying a bit on the colors of the stars, to imply that some are further away and give more depth to the piece as a whole.

I really like the character design and the font you used for the title. Got mixed feelings about the tiles, though.

Oh, and I don't really understand what those light-ish blue irregular shapes behind the close-up versions of the characters are supposed to be.

Yeah, it's cool. I like the characters, and the style. I think the tiles could be a little less flat, but it's a sweet title screen, nonetheless.

This is cute. Not a fan of the tiles though.