- Dungeons -
Each dungeon only needs 1 or maybe 2 puzzles about finding the way forward.
Most "obvious secrets" should lead to optional goodies such as treasure.

Another type of major dungeon puzzle could be an "open-the-way" challenge where you need to look for the key to open the main door forward.
This "key" can be themed around the level. A unique ability interaction, or "missing" pieces that you need to find the place for.
 One interesting idea I had was finding statue parts and looking for the correct statue that is missing that piece, in order to complete it. Meanwhile that dungeon also has many decorative complete statues.


Another idea is giving each ability a secret secondary use.
The player can be lead to inevitably discover this use via careful level setups.
 Place a innocuous-looking floor switch directly across a short water stream. The player already knows to jump over water. But by doing what they already know, the player will "accidentally" trigger the switch, discovering that it's possible to ALSO use jump to press switches. Ideally this discovery situation will be placed after the player has passed a few of these innocuous "floor tiles" in previous areas.
 Place a fake torch with leaves behind it. This "torch" resembles regular torches that the player already knows they can ignite using their laser. But when they attempt to light this fake torch, their laser will fly past it and ignite the leaves instead, revealing a secret passage behind them. This should be placed after the player has passed a few of these seemingly "decorative" wall leaves.


The "hot cave" can have flame-thrower barriers that toggle between 2 states whenever a switch is pressed.
A fun easter-egg is if one of your girl followers happens if be in the path when a flame turns on, they'll lose their clothes. (don't burn the girl, only their clothes) It might be even more funny if they don't even react. Just some smoke for a moment, and then they're just casually naked. (They end up naked often enough that they're all probably used to it by now)  It might be amusing to have them mention that a little while later.