I have to admit that the third-person animations are quite shoddy. Bethesda still has much to be desired when it comes to good-looking character models. Running, jumping, these should probably be less awkward looking if they're going to have a third-person mode. But once again, their first person stuff is alright. Shooting isn't really intolerable, as long as you stay a decent distance away from the enemy. VATS is a decent system, and the AP recharge at a decent pace. Melee weapons seemed incredibly superfluous and pretty useless (even with the melee skill maxed). It just seemed much more convenient to just shoot everything.
The main missions were good, but brief, as endnow said. Also, the ending is totally lame. They built it up, and then they kind of just...gave it a big anti-climax.
I have to say that it felt like they took Oblivion and shrunk it down, gave it even worse third-person, and gave it guns.
But all in all it was a decent experience, with pretty good replay value.