Thanks for the Feedback!
Did you unlock the Ammo types in the Lab ? After you have them researched, you can select between available ones with RMB (There are small ammo icons on the right side of your bullet UI) We will look after the freeze issue.
The game has a bit of a learning curve, we are certain that if you play a couple more times that you steadily increase. That is a big part of the appeal of the genre, but it also depends on which items and weapons you get and which perks you choose. Some runs can be unlucky in others you can get very lucky in weapons and items, don't give up : ) We will certainly add more difficulty modifiers and a easier one as the current normal/easy difficulty is really not easy, we are working on the balance at the moment, but if you beat the boss then you should be fit for the rest. I can try adding a real easier mode in todays patch. Keep in mind that the beta will end soon and we might change the price tomorrow.
The timed weapon cases are supposed to be rare bonus cases, they have higher level loot but lock after a time, so if you are fast enough you get it for free, else it will just become a normal metal crate with a keycard requirement.
Thanks for your comment, glad that you like the game!