It's not as daunting as a you for think for a Metroidvania without a map. The game is split up into sections where you eliminate all of the Metroids in an area and then move on to the next. The game really doesn't ask you to backtrack to the extent that Super Metroid or Dread might. This is probably the Metroidvania where I had to consult the internet the least, although the best method ro defeat the final boss is fairly obtuse. That said you should probably play it within the span of a weekend or so, rather than just pick it up and finish it later, so you'll have a stronger mental map.

To give this game a bit more criticism, I wish there was more than 2 area themes. I implied it's easy to find your way to the end, and it is, but some different tunes would be appreciated . Still this is one of the best Gameboy games in my opinion and definitely has all the Super Metroid vides down( as much as you can given the vastly weaker hardware).