A fine use of a few weeks of your life
People have been talking about crossing an FPS with an MMO for a while now and the game that usually springs to mind is Huxley. With that nowhere in sight, the bar has already been set very high by Borderlands. Combining an incredibly solid shooter with the quest structure of an MMO, a great set of random drops and a well implemented levelling system has worked out really well and made for a pretty unique experience.
I've spent a little over 30 hours with Borderlands, finishing the quest and all side missions and managing to drag out every achievement except "Hit level 50". It's likely I will continue to play as the second playthrough option is done really well, using the same quests but with a much stronger set of enemies than you saw in your first play, though it does feel a little weird being put through the tutorial again.
The sense of humour in Borderlands worked really well with the art style they've used. Cel shading fit the game really well and I think they made a wise decision changing the graphical style from the standard graphics they had planned.
The game's one real weakness comes from its greatest strength - the multiplayer. Having two or more players playing through the game at once works out really well for the most part and is a great way to experience the game - unless you are 2 or levels apart, in which case it completely breaks the game for one or both players. A higher level player joining a low level game gets basically no experience and tramples over everything they see, dragging the lower level player through the game and completely ruining the experience for them. A low level player joining a higher level game literally can't kill any enemies and is basically useless, getting experience for the kills and being dragged up too high to make their solo game worth playing. That all said, when you are of a similar level to all players in the game, it's a great deal of fun, with the game ramping up the difficulty accordingly.
Many have complained of the game's weak story and especially the ending. I have no such complaints and I'm not going to discuss the ending in a review, but I'm absolutely okay with it. The data tapes you find in some of the side missions tell a better story than most whole games do anyway.
I played a Siren assuming everyone else would pick Soldier. The Phasewalk ability was an absolute lifesaver throughout the game, healing me when I got in trouble and making travel between places much less tedious. I can't imagine playing as any other class but it's a sign of good balance when nearly everybody says the same about the class they chose.
Borderlands overall is a fantastic experience and it's nice to see a new franchise turn out to be one of the best games of the year.