Been playing for about 15mins. I've only come across two flaws. The first being that a lack of volume controls hinder the ability to focus (preference for lower music, higher important sounds).
The second is the controls feel "sticky" and slow to react. Something you'd get use to over time, but annoying in the first instance of meeting them.
Otherwise gameplay is simple and solid. An indicator of which weapon is attached to primary and secondary toggles would be useful. Music, Sounds and graphics are all otherwise spot on and atmospheric.
Rated 7/10 for fun :D