It's a good game if you're into the theme. If you've ever played Zombies!!! and thought, "Man. I wish this game were just a little better..." then this is probably the game for you. Personally, I played Zombies!!! and thought, "God, how did they make this suck so hard?" so after playing Last Night on Earth I was left saying, "Man. I wish this game were just a little better..."
Basically you run around fighting zombies on a semi-random board. There aren't enough interchangable pieces to make it feel really random and the board is always shaped the same way. Each turn you can either search or you can fight. Searching nets you cards out of the deck that might be weapons or items or might be special effects. The player controlling the zombies (or two players, though the 2-zombie-player variant was kind of weak, I felt) gets a fixed number of cards and rolls dice to see how many zombies he gets to spawn at the end of his turn with the difficulty to get more zombies increasing based on how many are already out on the board.
The biggest weakness with the game, other than that fighting without a weapon as a hero or doing anything other than swarming one or two heroes at a time as a zombie player is pretty much futile, I felt, was the lack of zombies. I forget the exact count but the game comes with somewhere between a dozen and twenty zombie figures. Once the zombie player runs out of zombies he can't place any more, so there's a pretty low limit on how many total zombies can be in play during the game. It's all balanced fairly well for the recommended numbers of players but I think that it really loses some of the zombie apocalypse feel when there are only, maybe, 3 zombies for every human on the board. For all the things it did wrong, Zombies!!! at least managed to maintain the whole "There's no stopping them. All we can hope for is to beat off enough of the zombies to make it to the helipad" feeling of your average zombie flick.
If you're into very light strategy-combat games, zombie games, or both then I'd say Last Night On Earth is a good one to pick up. It's at the very least rules light enough and quick enough that you can break it out at Halloween for a casual game night.