If you think the Game Gear was ahead of its time then you should take a look at the Atari Lynx. This thing is a monster for a portable console from 1989 and it's basically a pc-engine in terms of specs.
With great power came, well... great "size". The Lynx is as big as the Switch and almost as big as the Steam Deck, it also chews through batteries like it's nothing.
Unfortunately it couldn't compete with the Game Boy and the Game Gear almost immediately replaced it as Nintendo's only portable rival.
There's also the lacking game library, with few interesting games to play; the poor thing suffered the same fate as basically every Atari console aside from the 2600.
A really cool and unique feature of the Lynx is that it has two sets of A and B buttons so you can flip the console if you are left-handed.
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