Can Fire Aniimo burn environmental barriers?

In practice that means vines and wooden obstacles are not dead ends. If a path is blocked by something that can catch, you need a Fire form on hand rather than a key or a quest flag. Twining into the Aniimo is how you get access to it, so exploration works best when you keep a Fire type in the party you can swap into on the spot instead of walking back for one.

Burning is one case of a broader rule. Certain Aniimo forms and abilities interact directly with world objects and solve environmental puzzles, and fire is the most legible version of that. See a barrier, bring the element that removes it. When you hit an obstruction you cannot pass, the question is usually which form you are missing, not whether the route exists.

Fire does not cover everything. The open world also runs physics-based environmental puzzles, the kind where you replace a missing center piece, and those want the right object in the right place rather than a flame. Twining is also what gets you into areas you could not otherwise reach, so some walls are a movement problem, not a burning one.

Not settled: Vines and wooden obstacles are the confirmed cases. Which other barrier materials burn is not established.