It's exactly that design except you can't avoid battling certain "guards" that lead to smallish closed potions that have no other entrance or "minibosses" that are near some loot you want desperately to grab. But otherwise, you can just fly over or circle around a trashmob currently too hard to kill. Another possibility is to lure a hard to kill trashmob towards friendly NPCs who'll then kill it instead of you (but you don't get XP then).
In any case, trashmob levels don't scale with your level nor with levels of your equipment/skills like in Skyrim.
So yeah, it's monstergated openworld but not in a way these monsters require you to kill them all in order to reach some spot. Monstergated and openworld are not mutually exclusive here.
Also note that you can activate teleport spots on the map and fasttravel on them at any time ignoring anything you've avoided to kill previously.
EDIT:
In case you can't understand the combat system and trashmobs feel too hard which leads you to think it's monstergated linear game (here's hope Angry Joe sees this before reviewing the game):
http://steamcommunity.com/app/411300/discussions/0/1483233503861430860/
Thank you so much for this. It is and will be incredibly helpful.