UPD: aaahh the Spiral Knights! Unfortunately this game is past its prime now: it barely gets any new content (costumes and reskins do not count).
I should also point out that this is hardly any fun without solid friend base and a lot of people have moved on, sadly. Can't really recommend now.

Yeah, this looks like a kids game, though its mmo, so that first argument doens't matter. As with all mmo's one needs to know when to stop... spending money on it.

UPD: aaahh the Spiral Knights! Unfortunately this game is past its prime now: it barely gets any new content (costumes and reskins do not count). I should also point out that this is hardly any fun without solid friend base and a lot of people have moved on, sadly. Can't really recommend now. Yeah, this looks like a kids game, though its mmo, so that first argument doens't matter. As with all mmo's one needs to know when to stop... spending money on it.