I'd say old school. The puzzles and dungeon designs remind me most of A Link To The Past. However, there's a focus on throwing spheres to ricochet off walls (as that's the basis of the game's combat). So instead of having an arsenal of weapons (sword, boomerang, bombs, arrows, etc.), it's more about tossing balls to manipulate other objects equivalent to those items in each dungeon room.

For example, when you get the Fire element you can imbue your spheres to melt ice blocks, and also to launch bomb orbs further than regular spheres.