Maybe I'm just rusty but I'm finding these missions EXTREMELY frustrating. Way too many stealth missions where you have to walk in just the perfect path or you have to start over. And there needs to be more checkpoints. I've shut the game off in frustration more than once and I'm only on Sequence 3.
I'm also having a problem with the combat but again I'm rusty. If I'm surrounded by four dudes hitting me, I have to constantly hit the counter button and I'm never able to attack on my own, leading to long drawn out annoyances.