The American Heritage Dictionary defines "anthology" as:

1. A collection of literary pieces, such as poems, short stories, or plays
2. A miscellany, assortment, or catalog, as of complaints, comments, or ideas

Metal Slug Anthology fits nicely into both definitions of the word since it compiles 7 chapters of the classic side-scrolling shooter. The first definition is somehow fitting because there are well developed stories behind at least 5-6 of the games. Metal Slug fans recognize and enjoy the characters much more than would seem normal for a game of this type. Chalk it up to fandom or maybe to an excellent promotional budget. Or, you can just acknowledge that the Metal Slug games are damn good. They were good in their day and they've aged well over the last ten years.

The graphics improve from game to game as designers learned new ways to manipulate a 2D environment. Backgrounds become more dynamic and the character models improve. The final game includes some really impressive effects like objects swirling through the foreground and background around the characters. No slowdown or choppiness was evident in the PSP version. The screen modes include a full-screen option that really showcases the great graphics. The music and sound is great and ranges from a rousing soundtrack to the staccato litany of machine-gun fire. Playing without headphones is going to annoy your neighbors. The boss battles are incredible and even the mid-level bosses are screen-filling wonders. What is most impressive across all of these games is the lack of repetition. The easiest thing in the world would be to create a sequence of backgrounds and a recurring slate of 10-20 enemies. Instead of this, you get the feeling you are really exploring and discovering new territory and fighting a horde of enemies. This wealth of creative juice goes a long way toward explaining how a side-scrolling shooter survived for 10 years.

Metal Slug introduced a pair of scrappy soldiers, Marco Rossing and Tarma Roving. The characters were largely interchangeable but they fit into the story as members of an elite group tasked with shutting down the operation of General Morden. Only in pacifist, government-controlled Japan could a storyline originate where the soldiers of the government are straight arrows fighting against a power-hungry rebel force. Rossing and Roving are members of the so-called Regular Army charged with defending the country. The Rebellion Army led by Morden overwhelms the Regular forces and steals a prototype tank called the Metal Slug. With the Rebels intent on turning the country into a military state, it is critical that all Metal Slug vehicles be destroyed or recaptured.

The subsequent games were built around variations of this storyline. Some pieces of the story that became Metal Slug staples included the idea of playing multiple characters, rescuing prisoners, piloting vehicles, and destroying enemy firepower. Morden and his troops continued to mobilize throughout the years and needed a thumping not once or twice, but six more times! The second game introduced two new characters, Eri Kasamoto and Fio Germi, that appeared in later games. The idea of switching between characters for practical rather than novelty reasons popped up in the sequel. The other story element that changed some play dynamics for Metal Slug 2 was aliens. Apparently Morden enlisted some aliens (yes, aliens) to his cause in hopes of overpowering the Regulars. Fighting aliens and commandeering alien technology makes for some very interesting diversions from the original Metal Slug. The third game in the sequence is actually a rev of Metal Slug 2 with some improvements. The actual Metal Slug 3 is a fourth release that retained all the characters and featured some improvements in play mechanics and design. Metal Slug 4 briefly swapped Nadia Cassel and Trevor Spacey for Kasamoto and Germi, but Kasamoto and Germi return in Metal Slug 5. Both these games take focus away from Morden and the Rebel forces to introduce other threats to national security. The themes of the Metal Slug games moved toward more high-tech enemies and more complicated environments as the game-design horizons expanded. The final game in the series, Metal Slug 6, is seeing its first release in this collection. The depth of this entry is outstanding, with six playable characters and every 2D trick in the book employed to make things immersive and challenging. This installment would justify a purchase even without the previous anthologized entries.

Like almost every classic side-scroller, this is a difficult joint. Look up "unforgiving" in the dictionary and you'll see a list of the old games we played and loved back in the day. One hit didn't just deplete your shield back then. The closest thing in Metal Slug to a shield is the time during each game when you jump in one of the Metal Slug vehicles. The armor can take quite a few hits before exploding so you get some reprieve from the hail of enemy fire. The other thing that makes Metal Slug a tricky game is how the controls function. Shooting to one side or another is simple and you can press Up to shoot enemies above you. A diagonal shot factors into the mechanics for vehicles but the soldier segments are all about shooting Up/Down/Sideways. Jumping and shooting or crouching and shooting let you hit some of the more elusive enemies and you can jump and press Down to take shots at lower levels. The last point is where Metal Slug operates a little differently than some other games of its type. The requirement to jump and shoot in order to make some shots creates a more challenging control scheme that takes some adjustment. Luckily you can adjust the difficulty and turn on Auto-Fire through the Options menu to make things easier. It's not cheating... it's a strategy!

Some of the features for Metal Slug Anthology include a gallery of unlockable extras and a multiplayer mode. These are the additional pieces that were wrapped into this release. Multiplayer was obviously a part of the original games and it has been incorporated here for wireless play. Hosting or joining a game is as simple as selecting the chapter and character before jumping into other action. When you complete a game on one of the three difficulty modes, you will be awarded tokens that can be redeemed for locked content in the Gallery. Gallery items include featured art, promotions and music. Multiplayer will be a nice add-on for you when a friend is around, but you can spend time unlocking content on your own through the Gallery at any time.

The only other version of Metal Slug Anthology I had my hands on recently was the release for Nintendo's Wii. The Wii version included about six different control schemes related to the different controller buttons and motion control. The PSP doesn't have the same range of buttons and tricks up its sleeve, but it is possible to reassign buttons to fit the way you want to play. Maybe it was only because I had the experience of playing the Wii version, but I wanted more freedom to customize the controls. This is a tiny thing, like saying the salt could be more salty... Metal Slug Anthology belongs in the library of any classic gaming fan. If you're prepared to work a bit toward mastering these challenging games, they'll reward you with hours and hours of great action.