Some game series simply refuse to move on with the times. The Metal Slug series is one of them. Ever since its conception on the Neo-Geo 14 years ago, nothing has really changed. Nearly every platform known to man has been graced with its presence, but not one has seen a single new idea. Its Victor Meldrew-like stubbornness has endeared enough shooter fans over the years but not really anyone else, so don’t go expecting Metal Slug XX to welcome you with open arms if you aren’t one of those fans.

Originally released on the Nintendo DS nearly two years ago as Metal Slug 7, this belated PSP port adds a new character (via downloadable content) and a multiplayer mode for you and a buddy.

What little story there is involves a time travelling army going back to the past to save their future defeated leader and provide him with all the high-tech gadgetry of the future, so that he can beat his present day Nazi-esque foes. As the plot thickens, the supernatural elements of the story reveal themselves as does the series trademark tongue-in-cheek humor and general Japanese bizarreness that you’d have to be dead inside not to love.

Almost as endearing is the series unique art style, which favors hand drawn 2D sprites over 3D polygon graphics. The backgrounds are constantly altering, and the characters are equally expressive. The cartoony, animated world makes the always surprising gore and blood funny in a kind of Braindead sort of way.

But for all its wackiness, its prehistoric gameplay eradicates any good will that its sense of fun may have generated. Why (after so many entrants) can’t we shoot diagonally? It is beyond me and beyond the series’s cult following, which has been patiently asking for the option since 1996.

Though being a run and gun game usually involves little more than running left and right, a tad bit more diversity wouldn’t go amiss. Instead of just relentlessly shooting, mixing things up a bit would help with breaking up the monotony. Other shooters such as Gunstar Heroes and Ikaruga have shown that shooters don’t just have to be about shooting.

Purists will also argue that the lack of punishment for failure in the game maybe a sign of moving on with the times and a softening of the series’s roots for a new generation. Should you die, you’re immediately thrown back into the action with a fully restored arsenal. Personally, I view this as a plus. After all, why pay for a game that just frustrates you into giving up? That’s not to say that the game isn’t still brutally hard, but having checkpoints just makes it easier to get a grip on things.

In terms of the game’s lifespan, put simply, you could probably finish all seven levels on your lunch break. While in line with other Metal Slugs, the disappointing game length is made worse when you consider the price of the Metal Slug Anthology. There are an additional 70 trial levels known as “Combat School.” However, the repetition and difficulty will put most off.

Whether you buy this game or not all boils down to how much you love your Metal Slug and whether you love the fact that it has not changed one iota in nearly two decades. This could have been any other Metal Slug, and you’d be none the wiser, let alone the seventh entrant in the series. No, not the best position to be in, especially when you consider just how many other great 2D games are available nowadays.

It is, then, one for the fans, but surely, even they must be tiring of the formula by now. What SNK should also remember is that their loyalists won’t be around forever. They will get old and move on, and for the series to survive, it needs to be injected with some new ideas.