After the latest huge content upgrade, there are a lot of new factors that need extra care when tweaking the balance. For that reason, I've released a new update today that will tune a few things for a better experience. The Silenced Machine Pistol has some of it's firepower restored and the overall Monster spawn balance has been tweaked to be challenging but not unbeatable.
If you want to help me improve the game, check out the Steam discussion boards and tell me what you think :)
For the full patch log, go here: http://steamcommunity.com/app/321270/discussions/0/392183857627016240/