This is one of those comics a fan of comics as a medium should be aware of.
This review has an image that shows a bit of why: Structurally, Leo Geo is one of those Scott McCloud-type experimental comics. You need to reorient the book several times to read it (and change the structural order you read pages in), but it's incredibly natural and intuitive.
Despite the simplistic design of the titular character, the art alone would also be worth the read. The story is a strange mix of fantasy, science facts, and things that honestly don't make sense (though in a "I'm willing to ignore that because this is sufficiently fun" way) that... well, let's just say it's not really that much of a story, but it does what it needs to, which is give the artist an excuse to do cool and fun stuff and crack the occasional remarkably straight-faced joke.
"I can't (let the underground civilization invade the surface)! There's too much good solid science going on up there!" (Emphasis mine.)