iO is a platformer with a size-shifting twist. You control a ball, tapping on buttons to move it left and right.
But you can also control its size, swelling and shrinking it to fit through different gaps. Bigger balls roll quicker, and you can wall jump by increasing the ball's size in quick jabs.
It's a clever idea, and it's seen through reasonably well. Things get pretty tough pretty quickly though, with even some levels of the tutorial requiring perseverance and patience.
But if you like a slightly fiddly challenge then there's a lot here to like. Just be prepared to get frustrated while you play.
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