I'm not a massive fan of computer gaming. Browser-based gaming has never been part of my gaming routine and has ceased to enthral me despite purchases of newer and better computers on my part with faster Internet connections, also. But, just like if you're not too keen on The Beatles, you have to respect it/them for their impact of their avenue of media. The Beatles revolutionised the way music turned out by creating (a) new genre(s). Browser gaming changed the way we spend/waste our time at school/work... And I respect it for that.
I first heard about The Last Stand (TLS) when I was shown it when I was round a friend's house.Having spent the night there for a sleepover, we were both tired and bloody bored, too. Having played a couple of games on his Xbox 360, he moved onto his computer and surfed the net for a bit. He then showed me TLS and I loved it. I don't know whether it was the fact that I was 11 or that I liked a bit of violence at the time but killing zombies appealed to me immediately and immensely.
The game is a third person shooter where you are behind "cover" and you have to kill zombies to stop them from reaching you and eating your brains (once the cover is destroyed then it's usually over as the zombies quickly descend upon you). The rest of the game is spent finding survivors to help you kill the zombies or looking for weapons. You can have up to seven survivors, including yourself, with the seventh survivor always brandishing a hunting rifle which can take out a zombie in one shot, so my advice would be to gather survivors as quickly as possible in your daylight hours so as to quickly obtain this asset.
In terms of weapons, there isn't a massive variety for your wall but it's big enough so as to keep you satisfied. There's standard pistols then it moves onto shotguns then machine guns with quirky weapons such as the chainsaw adding a little bit of "ommph".
To be honest, it's one of only a few browser games which I play occasionally. I have always adored it and my love affair has continued with The Last Stand 2 being released and 3 having its trailer on YouTube. It's free. The link's below. Have a go. :)
The Last Stand - http://armorgames.com/play/269/the-last-stand