Take note of the time: 47:17. That's how long in minutes and seconds it took us to complete Metal Slug 5, and that included at least one toilet break, and a quick perusal of our emails to check out a highly inappropriate comedy mpeg involving a kangaroo and an electric fence.

See, the thing is with the Metal Slug series is that together they'd form a perfect big lump of a retro collection, but as standalone releases at a few notes a pop it doesn't half seem cheeky.

So, what of Metal Slug 5 as a whole, then? Well, there's that finish-it-in-your-lunch-break lifespan to worry about for starters, and the infinite continues turn the experience into something of a no-brainer, but the real stickler is the fact that many of the levels seem to be ripped straight out of Metal Slug 3, mini-subs, jet-packs, and tanks included. There's just no surprises, and certainly no kind of challenge, regardless of however explodey and colourful it may appear.

Another strange omission is the novelty zombification mode, where you could get turned into a zombie and hurl stinking zombie vomit at your enemies until you got hit again and died. In this instalment, however, the zombies are nowhere to be seen. Tsk, and so on.

There's your usual kooky arsenal of weapons too, but not exactly anything we haven't seen before. Firing off gut-busting rounds of rockets, lasers, incendiary devices, and bouncing mines all seems a little less impressive as it did, oh, about five games ago. One new device (at least we think it's new) is the wind-up clockwork mouse bomb, a sweet touch that's overshadowed by the redundant feeling of just about everything else in the game.

In an arcade cabinet we've no doubt we'd fall head over heels for Metal Slug 5's batty retro charm, and we know for certain we'd have spent more than £20 on ten pee pieces getting to the end. But on the Xbox? No, we're afraid it just doesn't wash. What's the point in playing a game with such a fatally limited lifespan, and where any challenge is removed by what are essentially built-in infinite lives?

If SNK even dares to release all the Metal Slug games as a complete package after asking us to form out £20 a time for each one, we're going over there with a hammer and a blowtorch. It's certainly worth 45 minutes of your spare time, but it isn't worth the inflated asking price. It's fun, it's daft, but it's bleeding us dry and feels like an oh-so pitiful regurgitation of what we've seen so many times before in this series.

1. Well, it's certainly pretty, it's certainly colourful, and that 'cock-rock' soundtrack, well, does the job. So to speak.
2. Is it, as far as we know, the last Metal Slug game to appear on Xbox, which means no more getting ripped off £20 at a time!

1. Haven't we seen this all before in the previous games? We never thought jumping in a jet-plane could get as tedious as it does here.
2. Why can't you turn into a zombie? Sure, it was part of Metal Slug 3's story, but we at least expected something to be added, not taken away!
3. It's waaaaay too short, and with a Live play option still nowhere to be seen, we almost feel cheated from our money.

There are only so many ways to do an inventive side-scrolling shoot-'em-up. Five times is too many, we're afraid.