Metal Slug XX is so much fun that you can forget its main issues. It's a short game, it has almost no new features and it lacks depth at every level. But it's sheer fun, with great replay value and one of the best coops out there.
Metal Slug XX isn’t necessarily cheap. At $15, you only get seven stages. Sure, you can stretch the experience with co-op play or limiting your continues, but this is an arcade game at heart – longevity is supposed to come from repeat plays.
In short, the game presents a slice of quick-action pie to pass the time but won't keep you anchored for any impressive stretches of time. At the hefty ol' price of 1200MSP, I can't recommend a purchase, 800 would have been far more reasonable.