Hi! I appreciate hearing your thoughts.
Everyone seems to have their favorites among the spells. For everyone I've heard telling me "Earth Magic is useless!" I've had someone else insist it's their favorite spell. Certain magics work very well on certain enemies, and not all players seem to get the enemy weaknesses. It's also tough balancing spell costs. What seems expensive in the beginning may end up infinitely spammable in the end, especially since there's a relatively high magic drop rate.
I totally hear what you're saying about there not being more areas you have to return to open with later spells. In many cases, it's for purely technical reasons. Earth magic is a scripted weapon without built-in triggers, so every time there's a trigger I need to set up a script. The same is true of Dark magic, with the added difficulty of trying to put the switch out of reach. That, and the relatively small size of the game, make it hard to tuck away magic-triggered secrets without designing whole rooms around it.
While I understand most of your criticisms, it's tough to do anything about it. In a lot of cases, I've sort of built myself into a corner. I understand it doesn't mean much to a player experiencing the end product, but all I can say is I've done the best I can.
Thanks again. I'll definitely keep your impressions in mind.