Metroid is an NES classic, one of the first games to feature truly nonlinear exploration. It’s a game that manages to feel much larger than the sum of its parts (at least until you start planning out speed runs). The concept of needing to collect certain abilities to progress, rather than just defeat bosses or collect arbitrary keys, is a core innovation of this game.
One of the technical novelties of Metroid was its combination of vertical and horizontal scrolling. While the game couldn’t do both at the same time, its mixture of horizontal hallways and vertical shafts allowed for a sprawling map that you would be well advised to put to graph paper. It’s a game with many paths, some of which are littered with upgrades and secrets, and others are just a waste of time. The secrets of Metroid are one of its greatest strengths, but can also be a glaring weakness. This is a game where shooting or bombing random squares will not just reward you with upgrades, but in several cases is required to progress at all, which can be frustrating.
The difficulty curve of Metroid is another source of frustration. You have two main resources to manage, health and missiles, and dying will leave you with very little health (only 30% of your initial maximum, even if you’ve gotten energy tank upgrades). There is no fast way to regain health or missiles, so dying at the wrong time can lead to large time sinks, either dedicated to getting health drops or repeatedly trying to fight on and dying due to a lack of survivability.
Fortunately, the various upgrades you’ll find will make your life considerably easier. Missiles are very powerful, and you get quite a few of them. The hidden Varia and Screw Attack also massively increase your survivability, cutting your damage in half and turning most of your jumps into invincible death spins. Both are quite hard to find, of course, but that’s what Metroid is all about. It’s one of those odd games where it actually gets much easier as you progress, assuming you find everything.
Metroid is a great game in concept, and in the long run it lives up to its potential. However, a typical playthrough can be a mess. Enemy placements are cruel and often blatantly unfair, the game suffers from massive slowdown in crowded areas, and one bad jump can be very costly in many areas. The ending you get is based on the time it takes you to complete the game, and you probably won’t earn a very good one the first time through. However, Metroid offers a sort of New Game+, allowing you to restart the game with all of your abilities (minus collected missiles and energy tanks), letting you power through the whole thing quite quickly. After the frustration of a first play through, this can be pretty therapeutic.
The existence of Metroid: Zero Mission, a remake/addendum to this game, means you can have the full Metroid experience even without the original. This game is not as finely tuned as its sequels, particularly in the realm of difficulty. But it’s still a lot of fun, and a very impressive game for its time, early even by NES standards. I recommend giving it a shot, but don’t be afraid to check a map or guide if (when) you get hopelessly stuck.