-There are multiple maps that are somewhat open, but following the story streamlines you through some very linear locations, the last two chapters’ locations were practically FFXIII in a nutshell.
-60-100 hours. I powered through until I was getting aggroed and killed every time I tried to skip fights. I then did a bit of grinding and wiped the floor with the final chapters. The final bosses were a joke to me, but I did have a certain character set to heal me on criticals (52% rate) and spam the same art over and over. I finished at 90 hours and level 76 (boss is 70). Plan to screw around until I get bored or do a new game plus challenge/god mode.
-Enemies ridiculously over your level are normal. Some places you HAVE to run like hell. The worst offender is when heading to a factory, you’ll know when you get there. You’ll be level 30 and have to sneak around level 80 enemies.
-Pay attention to the tutorials, they’re gone once you press A. Thankfully we have the internet.
-There is a post credits stinger, but it may or may not actually ruin the ending for you. If you enjoyed the tone when the credits rolled, skip it and look it up later after the impact of the ending has worn off.