All the awesome flash games. Wasn't super early but there are 3 games I loved but don't remember the names of them...
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build a rocket bit by bit and try and fly it higher each time as your fuel runs down. Eventually you get into space. 2D.
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you are a penguin, it's a ski slope distance game. Get power ups and go further each time. I think you have a hang glider thing. 2D.
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A paper plane distance thing by Microsoft Xbox where you throw it through a window and there's sounds of kids playing. 2D.
Also Monkey kick-off. Another fave.