An awesome idea would be a fighting robot. Sure, they probably have one, but not one that destroys the other. So they can listen to you if you say "punch" or "kick" and they will do that. Maybe parts could fall off so that they know who wins. Kids would go crazy for that.
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Nallycat's This Robot I Am Calling Nallycat
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Donesvarc's Wall-E From Czech Republic
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