I know all the secrets by heart from playing it as a kid, and while clunky, it is a fun challenge to beat within the time limit to unlock the best ending.
Simon's Quest doesn't deserve to be called a bad game. The music and graphics are quite good for the NES and the open structure of the game was quite novel and many elements like the leveling system became staples of the series from SotN onward. The thing that really holds it back is the terrible english translation which makes the puzzles way harder than they need to be.
I always thought the game was really good. I played it for days as a kid. I never got far because some puzzles are pretty much impossible to solve without a guide as far as i remember. I loved the day night cycle, even tho they went kinda crazy with it.