The games are generally pretty fast and brutal, like a gunfight should be
The rules are pretty easy, it's a laid back kind of game. The format is "I go you go" but it's 1 model at a time. You activate one of your guys and move and shoot with him, then your opponent activates one of his, then you activate another one of yours and back and forth until every model has been activated. Then the next game turn begins and you can activate everyone again. Just keep going like that until everyone on one side is in the ground
The starter sets have 5 guys in em, and that's the minimum you need for a gang. But, you don't have to just use your 1 starter set, you can mix and match people from any set if you want. I prefer games of around 10 or so models per side. You can balance your gang with Fame points, so if both sides have a gang of equal value or very close, then it will be balanced. Or you can just go by model types and count. So, say you have 2 starter sets together for a 10 man gang with both the Secret Fist and Clancy Gang fighting together, you can have an evenly matched game against someone playing the Vigilance Committee and Bloodwolf Tribe. Or, you can even just use the figures and design your own gang from scratch, that's usually when you'll have to pay more attention to your gang's fame levels.
One thing though is the game works best when you have a lot of cover to hide behind. Just 2 buildings on a 4x4 board would be a pretty fast and deadly game. You want to have several buildings, carts, crates, fences, trees, etc, especially if you are using more melee oriented guys. You get a bonus to your defense if you're in cover, so don't leave your guys out in the open if you can help it