On the eve of my co-op completion of Borderlands, I felt it only right to take the time to switch things up and give a little insight into the apocalypse style world of Pandora (Na'vi need not apply). For the sake of atmosphere, listen to "Ain't No Rest For the Wicked" while reading this post.
The opening cinematic is narrated by Marcus Kincaid, your character's bus driver and purveyor of weapons and ammunition. Following his explanation of where the hell you are, you're given the option to choose between four different characters: Mordecai (The Hunter), Roland (The Soldier), Lilith (The Siren), and Brick (The Berserker). Each character specializes in certain weapons, but their real draw is Action Skills, unique to each character: Mordecai has a pet hawk named Bloodwing, Roland can deploy a sentry turret, Lilith possesses Phasewalk that allows her to turn invisible, and Brick gets angry and kills everything.
Marcus shortly kicks you off the bus, where you are greeted by the, sometimes lovable, and other 90% of the time annoying, Claptrap. The game throws you right into the mix with a, move-at-your-own-pace tutorial that gives you the jist of the game's mechanics, followed by your first friendly NPC (Claptrap doesn't count) and the beginning of a seemingly endless chain of quests.
One of my favorite things about Borderlands is that, while many areas are "off-limits" until you complete story-related quests, you are still given a lot of room to explore and trust me, you will. The creators of Borderlands aren't shy about shoving treasure into every nook and cranny of this game. However, like the original Fallout games, you will be punished for treading unknowingly into high-level territory (Alpha Skags are your worst nightmare for a long time).
This leads me to another favorite feature: Second Wind. When you are reduced to 0 HP, you will enter "Crippled" status, at which your character will scream for help and take a knee. The words, "FIGHT FOR YOUR LIFE" will appear, along with a draining red bar, signifying the time you have left before you expire. This works in two ways: a co-op ally can come revive you , before your bar drains and you are teleported back to a New-U Station (for 7% of your credits), or you can kill an enemy for a Second Wind, which will fully restore your shields but leave you in critical health.
One of the big draws to Borderlands is the dark, campy humor, reminiscent of hilariously bad 80's movies. Unfortunately Borderlands doesn't feature much voice-acting outside of "HEY" and "RAHSDUHDAH." Following suite, you can see the game itself mature on playthrough. In the beginning it seems kind of goofy, the cel-shaded graphics ring of a childish tone and the jokes are often facepalm worthy, but as the story progresses and your search for the Vault becomes more serious, the game itself becomes more serious. Enemies begin to look like enemies, rather then baddies you'd see in a Bruce Campbell movie, and the quest flavor text becomes richer.
The one major flaw I found in Borderlands is that, if you want a challenge, you cannot explore: you have to do the quests and the quests alone. If you, as my friend and I did during this co-op playthrough, explore other areas rather then jump right to the task at hand, you will find yourself over-leveled and laughing at the enemies feeble attempts to kill you (example; I have a blue quality shotgun that shoots nine bullets at once and at close range, I kill basically every enemy in one shot, and I'm playing as Mordecai).
Other than that, which is an easily remedied ailment (you end up going to every location on your map anyway through quests), I would have to say that Borderlands has easily Phasewalked into my heart. And for those wondering, the level cap, with the four additional DLC (there's a Game of the Year Edition out as well that has all four DLC packs with it) is 69. For comparison, my friend and I are level 35 and have clocked in about 20 hours worth of game time.
Now get off my bus.