there's a bit of a glitch if you select an orb to place but upgrade another orb first you can still place that orb even if you don't have the mana but you will go into the negatives and have to work your way back up
you need to work more on the details. as a developer you have to think about what is going to make the player interact with the world the way you want them too for example the use of a keyhole to know to use the key or screws to know to use the screwdriver... I hope you can take everyones criticism and make another escape game.
no way i swear when i started the game before this one that I could throw horizontally ridiculously fast just couldn't throw very high until i leveled up my strength