If you've read the above comment, I think spoiler warnings on anything below are probably redundant, but I'm putting a spoiler warning here anyway.
Same! After failing to beat Whirlin by turning myself into a pickaxe, and realizing too late I was supposed to transmute the wand instead, I assumed that what I transmuted the wand into mattered. Naturally, I went with the bomb. I guess I can see where blowing up Whirlin might have spoiled the intended ending, but have to admit I was a little disappointed by the lack of fireworks.
That's not to say I was in any way disappointed by the game! It was a fun set of puzzles, and I enjoyed the story very much.
I would suggest one change in the (understandably unlikely) event you ever feel like putting out a new update - it would be nice if after reaching the the endgame screen, there was an option to continue exploring for post-game content, rather than having to reload a save. It's a minor inconvenience as it is, but it seems like it would be a simple enough thing to add.