Not hard at all. Had it all done in less than 1 hour.
I streamed the game yesterday, just to show to 2 of my friends who were in a party with me. Little did I know that, after starting, there were 94 people watching. First time I did this. I couldn't let them down, so I played from start to finish, took me about 1h45m. That was fun.
Near the end I totally forgot what I was supposed to do and someone steered me towards the goal in the chat. That was the part where you have to trick the enemy into throwing bombs in order to open a passage on the floor.
Somehow I missed 1 achievement though. It's a secret one, so I coudn't tell you what it was. Anyway, great game as always. Few improvements to graphics, but the sound is really good.