I noticed the frame rate too, but the game is out in two and a half weeks so to see.
For the walking simulator comment -- I don't agree. I had that impression before I played the games, but Frictional's games actually have quite a bit of gameplay to them in terms of puzzle design, physics control, & encounter design.
In the gameplay video we see the set-up to a puzzle, there are traps in the environment, and how the game uses physics and environmental usage. In fact the gameplay present shows a number of small gameplay scenarios taking advantage of the setting. It has an adventure game focus more than an action game, but I think when in the span of five minutes they very clearly showing gameplay interaction and a few early gameplay scenarios (prepping the tanks systems, handling traps, the grenade trap moment), that sounds like generalizing more to me than anything.
