This is a bug that I recently discovered when I was editing example-bs1st to make it more like the Broadcast Satellaview game. If you change the frame rate of Aquamentus from 0 to any speed, it will behave very erratically. It will head either forward or backward (instead of moving back and forth as usual). It will eventually walk off the screen, ignoring "no enemy flags" and such.
Aquamentus wanders off the screen when you change its frame rate
Fixed. You can recheck it with this build: http://filesmelt.com/dl/zelda-w5.zip