Can Aniimo solve environmental puzzles?

The way you actually use a creature on a puzzle is merging. Merge into an Aniimo and its abilities become yours in the field, so the thing that clears the obstacle is the same kit you fight with. That makes your active lineup a traversal loadout as much as a combat one. If nothing you are carrying has the right field ability, the puzzle stays shut and you come back later.

The puzzles in the open world are physics-based rather than riddles. Some are built around a missing center piece that you have to put back in place. Others are keyed to an element, and water puzzles are the clear example: a water field ability is what lets you interact with them at all.

Treat this as part of how the map opens up, not as optional side content.

Puzzles that gate the map

Some field abilities are not a shortcut, they are the only entrance. Specific overworld areas are reachable only once you have the Aniimo whose field ability opens the way, which means chunks of the world stay closed off until the right creature is in your party.

The practical habit is to note the puzzle and move on. Catching or building toward a different Aniimo is the solution, and a spot that looks impassable on your first visit usually is.

Not settled: Which Aniimo carry field abilities, and which element each puzzle type answers to, is not laid out anywhere in full beyond the water case.