Is the whole game like this where if you move forward along through an area you're unable to backtrack? I'm only just starting out in the town, but every-time I go through a door or progress the game prevents me from going back to search, which is annoying because there are important items and secrets and I'm never sure if I go to a certain place if it will prevent me from going back again, which happens A LOT.

Definitely take care to not go through doors or across bridge unless you're sure you've thoroughly searched the area. The 6/6 secret areas are relatively early in the game and unlock your backup weapon slot. There was actually a few locations I completely overlooked until I played through the areas a 2nd time. One thing I like to do is use the 'Z' key to have the light show me which direction to go, then I'll usually explore all the other possibilities first before heading in that direction.

Yes, I do that exact same thing. This is the only game I can think of where the only time people use the "where to go" button is so they won't follow it. At one point my friend was watching me and asked me if my character has magical farts because the only time he saw me use it was to make sure I wasn't going the right way.

Its a linear game. It should have been obvious you couldn't backtrack. If things you missed were really important, they wouldn't have been missable. Accept that you passed things and move on. Get them on the second play though.

Just because it's a linear game doesn't mean you shouldn't be able to back-track especially with all the vital secrets and extras. Really miss the old days of first person shooters when levels were more than just one streamlined path going forward and you had to actually explore. Was kinda hoping this game to be more like Hexen/Heretic as opposed to Gears of Demon Forge