Pretty nice overall. Some of the AA is not working (hair to underside of hat for example) and some of the colours are not really conform to a RGB555 unstretched layout. Some of your colours have RGB values not ending in either 0 or 8, which is all you get in unstretched 15 bit RGB. Minor stuff, just letting you know.
Wow, this looks great! \o/
I really loved the colors used in the title! Altough, the dithering in the edge of that big glasses looks a little weird. (Sorry for my bad english, not used to it.)
what ptoing said. few minor changes would make it perfect. but what I especially adore is the rather "Amiga feeling". That's the way I feel it. Good job!