Thumbs SIDEWAYS... the single player campaign is a fun mashup between a tug-of-war, tower defense, and scroller rpg. You play to ear credits to level up skills and can even build your own castle. Eventually you get all stars on all maps, and all skills, and you are still left with an onsluaght-style game which is chaotic and challenging. Single player? Thumbs Up!
Multiplayer however, is a seriously broken, unfun joke. You are given 20k credits. Once you spend them, they are gone - you cannot gain new skills, you cannot reset your 20k to buy different items... EVER. Playing against friends? You gain no credits, so theres no reason to play with them.
The only way to get new credits is to play "ranked" matches which pit you randomly against other players (level 1 vs level 100 anyone?)- and in ranked matches you cannot even choose your opponents, so forget about ever playing with friends.
Multiplayer is horribly designed and very broken, slow and utterly fail, and unless you get this game at a steep discount, or dont mind playing by yourself, I'd say "avoid"