I think, given a long enough time span, Far Cry 3: Blood Dragon is a game I might have played twice. It's got a distinctive artistic sensibility and is both funny and easy to play. It's not a bad way to occupy a long evening alone. However, playing it two and a half times in the space of a week is probably not the best way to enjoy the game.
It wasn't bad, but I simply had no interest in rehashing the story so soon after finishing it the first time. There's only really one central joke - that this incredibly corny story is being told dead seriously - and while it's a good joke, it doesn't gain anything by repetition. And since the rest of the game was similarly shallow, with no alternate paths, varied character builds, and only a minimum of hidden lore, there was really no choice for me but to put it into easy mode and berserk my way through (I suppose I could have tried hard mode and stated taking the stealth seriously, but I don't think I'd have enjoyed that).
My final verdict is that Blood Dragon is probably an excellent DLC (I can't say for sure because I never played the base game). It's a fast and furious romp through an intriguing, if underdeveloped fantasy world. However, it never quite grows out of feeling like a DLC. This game is a diversion. Something you sink a few hours into and then forget about. It's good that such things exist, but I don't think they can necessarily stand on their own.
Of course, part of this assessment comes from the fact that I am biased towards epics. If it's a game I like, then by six hours, I feel like I'm just getting started. I know that a lot of indie games try to deliberately break from this paradigm and embrace shorter, more tightly constructed stories, but Blood Dragon doesn't really feel like one of those. Its pacing is off. You can get advanced weapons, but have no time to actually use them. The difficulty curve doesn't really ramp up over the course of the game. There are only seven story missions, so the later ones don't feel that much more difficult than the earlier ones. It wasn't like Portal, where every subsequent chunk of its two-hour runtime was used to introduce a more elaborate puzzle than the ones that came before.
Judging a game purely by its length is ridiculous, but you can't ignore the fact that padding, grinding, and side-stories are historically important tools in the game-maker's arsenal. Used poorly, they can stretch a game out way past what its minimal ideas are capable of maintaining. Used well, those things are the game, creating a sense of scale and progress in character power and making the world feel more alive. I'm not sure exactly how much Blood Dragon could or should have been stretched, but I do think it could have endured at least a little more. (At least enough to make sure that I didn't spend the last hour of each playthrough grinding money for my last few gun enhancements for absolutely no reason but the thrill of 100% completion).
In the end, Blood Dragon was a series of fun, but not too deep shooting/stealth (ha!) mission that served as a platform for watching a series of hilariously cheesy cutscenes, and it's probably not the sort of game that you should play two and a half times in a row, but the first time was pretty great and the subsequent times were entertaining enough to not be a terribly onerous burden. Maybe I'll have to pick up a main-line Far Cry game some time and see if it stacks up.