I pick Dracoid Ruins from Lands of Lore: Guardians of Destiny.
This covers basics, though they didn’t get the hidden chamber near the throne, as far as I can tell, nor the mysterious Wizard’s Tower, buried to the left. You can also see the opposite coast, lit by torches, which you will eventually get to by lighting all the torches with a spark spell, opening up the zone, area by area.
Some of the areas had shafts, and elevators, or rooms separated by rivers, which you could cross by finding floating objects, or solving a puzzle. (Spoiler!) The entire zone floods at the end. Meanwhile, the earth shakes, and you can hear windchimes in the distance, while debris falls from the ceiling, as if the whole ruin is about to collapse.
Lastly, a few rooms were distinct, and hand painted, and allowed you to interact to solve puzzles, much like Myst, where you placed an item in a container, it might open up a new room, and of course the usual “jumping” puzzles typical of platformers, where you could fall right off ledges.
I liked how the mouse was controlled in first-person, where you could left-click to attack. But you could right-click to detach the mouse, then right click again to toggle it back to mouse-look. While detached, you could click on objects, manipulate the environmental physics, and pick up items or move them, including doors, by left-clicking. Far ahead of its time…
Hitting the right mouse button would reattach the mouse, toggling back into mouselook, where you could left click to attack. While in right-click mode, you could use the left mouse button to move items, such as stacking crates, while right clicking again would re-attach the mouse.
Basically, a toggle switch. Switching between spells used the scroll wheel, if I remember correctly, or an up/down button on the keyboard, which slid between spells, certain of which could be hot-keyed.
You could also change the effects of skills using various herbs and alchemy, such as changing a lightning spell into a fireball, igniting torches, instead of shocking objects, or an oil spill, for instance. This came in useful in a variety of puzzles.
I mainly liked that the toggle/switch allowed you to directly interact with the physics, in the same manner as Penumbra, and Amnesia: the Dark Descent, while still allowing you to move around, and attack using the left-mouse.
Lastly, once magic was selected, it was cast using a single keystroke on the keyboard, making things very simple.
The longer you held down the key on the keyboard, the longer the spell charged, making it up to five points more powerful by the on-screen indicator: so a fireball spell could cause a minor project, or a major explosion, based on how long you charged it in front of an enemy.
The game also allowed you to shapeshift into a lizard, exploring smaller nooks and passages, useful for getting into locked places and to solve puzzles. The monster shape could move boulders, and heavier objects, out of the way, opening passages previously locked.
The entire zone was massive, and it contains several sub-areas, more than I can go into. Spanning several kilometers, you could see the opposite coast, where you will eventually arrive, assuming you solved the zone. Several of the secrets, to this day, remain hidden in my mind, such as a zone opened by a key under the throne room, which was full of cabinets, and showed something hidden on my map–yet I was unable to access it, and the entire zone seemed useless, except you could interact with cabinets, and stack chairs and crates to peer into the upper ones. The puzzle remains unsolved in my mind.
I want to see branching dungeon design like that again… HUGE dungeons.
P.S. Any chance we could use a detachable mouse design, like the one I described, with a toggle, to solve puzzles using environmental physics, like Penumbra, or Amnesia?
P.S. Forgive the narrator. He’s a bit annoying. xD