Recs.
Updated
Payday 2 is a team-based first person shooter and strategy game, where players are tasked with performing all sorts of criminal activities (such as robbing banks and robbing stores) in order to gain as much loot and money as possible.
SpecsUpdate
Pros
Pro Lots of customization
Most aspects of the character are customizable, and lots of it affects how the heist will play out. For example if you want to be heavily armored, you will be detected quicker. Or if you are hitting a bank with a lot of deposit boxes you might pick a saw instead of a secondary. And on top of all of that there are skills to pick for specific specializations.
Pro Cooperation based gameplay makes sure no single player is more important than any other
Your crew needs to bring specific equipment and weapons in order to stay out of sight or improve everyones chances in a gunfight. You also need to pay attention to your crew's health and ammo. This creates a situation where each team member heavily relies on the rest in order to succeed.
Pro Tons of customization options lets every player individualize their look
You can customize your weapons, masks, and skills using the loot you earn from your heists. This lends itself well to the fact that the game is online multiplayer, being that most players enjoy that they can look different from other players.
Cons
Con Microtransations that boost important stats
With Crimefest 2015, the developer (Overkill) decided to add stat-boosting gun skins that can only be acquired using real money. This makes for a pay-to-win scenario where people who purchase these items have a distinct leg up over non-paying players.
Con Pay-To-Win Scheme
As others have said, this game is built on DLC and MicroTransactions. If you decide to just buy the game and not fork out any more money you'll find yourself at a SERIOUS disadvantage over other players. In addition, a lot of in-game items require you to either own other games or subscribe to specific Steam groups.