The ideas behind the sigs are nice, but they're much, much too cluttered.
Did you really need to put ALL the legendaries from Kanto to Hoenn on one sig? It just screams that you wanted to use them all at once. It makes it really hard to focus on one Pokemon with them being so cluttered.
Making a set of sigs- say, one with the three birds and Lugia on, or one with just Mewtwo and Mew on would've been better. Then you could have the practise of making more sigs, too, if you make a series.
Also, try using something other than the 'version' sprites- they don't always look that good. You can easily get hold of the Mystery Dungeon, overworld and Pinball sprites if you search well enough. These sprites aren't used much but they're more interesting sometimes.
Oh, and I agree with Mudkipman. What he's said is true too.
They're pretty good for a beginner's, though. Keep practising and you'll get it nailed. Remember- we're not bashing you, we're making suggestions to help you improve
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