I'd say the game is above average for 1987, frankly a lot of these concepts had already been done by Metroid at this stage and this definitely doesn't compare to that or Zelda II from the same year. It just feels a bit unpolished in some areas, the combat especially feels a bit iffy. Outside of the lack of polish here and there though I think the structure of the game is sound, the boss fights are a little ahead of the curve (I especially like the boss that grows throughout the battle) and whilst not the best action adventure game of the time, its still an early, pioneering game for the genre.