This is easily the most ambitious Adventure Island game. Adventure Island 4 (only for Famicom!) comes close by being a Metroidvania, but this goes even further than that by adding small RPG elements like random encounters on the overworld and several sets of armor and weapons. Between these things and the magic spells you can collect, you could say there's a lot of Zelda 2 influence.

This is definitely my favorite Adventure Island game. It's pretty much a great game, the actual design is quite fun. But it does feel a little undercooked, or at least under-budget. The graphics are somewhat lacking for a late SNES game. The backgrounds can be a little ugly and sparse, and the animation is noticeably limited. The game transitions between areas by abruptly cutting to black, which feels really cheap, and every scene change takes a few seconds to load in which is very unusual for a Super Nintendo game. When you kill a boss, the screen cuts to black and then it drops you back in the room but with the treasure spawning in. I don't remember running into any bugs that actually messed with the gameplay, but all of these things give the vague feeling that this game is held together by duct tape, which is an odd impression for a 16-bit adventure game of this scope to leave.

This is still a unique and enjoyable game, and the music is great. I just wish it'd been a little more polished.