Secret of Evermore definitely is glitchier than the average game, and its glitches are definitely of significance. We're just lucky that they're not really easy to trigger. If you're progressing through the game like normal, you're fine, but attempting to go where you're not supposed to can be a recipe for disaster. Although based on SparTonberry's link, the European version didn't address any of those and only fixed the one glitch that didn't really matter, haha.