Most of Metroid centers on the process of exploration, eschewing the arcade-borne concept of difficulty (death and restarting as a penalty) in favor of something more esoteric. Samus certainly blasts her fair share of enemies en route to the end, but Metroid lacks bottomless pits or instant death traps, and the more gear you acquire the more difficult it is for Samus to die. By game’s end, you’re an absolute juggernaut. The trick is in figuring out where to aim that firepower — and if those solutions can sometimes feel needlessly obscure, well, Metroid takes the same approach to secrets as contemporaries like Ghosts ‘N Goblins did to enemy collisions: Hateful and mean. It’s primitive, but at least it tried. And we’ve gotten better at this sort of thing thanks to games like this paving the way.
Once you do figure out the nature of Metroid‘s secrets, however, don’t go thinking it’s smooth sailing all the way to the end. Nintendo R&D1 remembered to put a few road bumps in along the path, including the mini bosses.
I’d be interested to read a debate over which video game introduced the first boss. Was it the Galaxian flagship? Wizardry‘s Werdna? Donkey Kong? Sinistar? I don’t know! But I do know that Metroid took a very unconventional approach to its bosses. Rather than treat them as obstacles to be overcome — impediments along the straight path to the end — Metroid‘s mini bosses instead represent one of the game’s main objectives in and of themselves.
The non-linear nature of the game meant that you didn’t simply encounter these guys on the way to the flagpole at the end of the stage. Rather, they served as load-bearing supports (as it were) for the final boss, with their deaths opening the path to the end game. To complete the game, players need to seek them out, actively, to destroy them. All the tools and weapons and items you collect en route are merely means to an end. What you’re really after is the bosses, whose deaths pave the road to the conclusion.
The first boss, according to placement relative to the game’s beginning and every piece of literature I’ve ever read about Metroid, is Kraid. Like I’ve mentioned already, though, Kraid is by far the more difficult of the two mini bosses. Well, so it goes. In terms of backward difficulty curves, Metroid has nothing on its sibling Kid Icarus.
Each of the two bosses lives in a lair on a platform surrounded by toxic fluid. The recoil from their attacks can easily knock you into the liquid, and unless you have the High Jump boots you may not be able to get out again. But the greater danger is by far is in their direct attacks. Kraid fires two different kinds of projectiles along two different paths: Large horns that fly overhead on an arc, and short spikes that fire straight ahead in a burst of three.
The primary danger comes in the form of the smaller spikes, which don’t simply fly toward Samus — they also deflect incoming fire, leaving only a small window of opportunity to pump Kraid full of missiles before the spikes regenerate and fly again. The overhead horns serve to complicate matters. It’s easy enough to jump over the spikes as they fly forward, but in doing so you’re very likely to leap into the path of the horns.
The smartest solution is to freeze the spikes with the Ice Beam, taking them out of play for a few seconds and leaving Kraid vulnerable (since his spikes won’t regrow while other spikes remain on screen). However, even this requires caution, as frozen spikes block missile fire just as effectively as “live” ones. If you make the mistake of freezing the spikes while they’re still lodged in Kraid’s abdomen, you effectively make him invulnerable to attack. So, you need to wait until the spikes are flying — and you need to freeze them precisely, as the three spikes function independently and a sloppy shot can leave some in play. Out-of-sync spikes are the worst, since they fly at staggered intervals and make your attack even more difficult to time (and make you even more likely to take a few hits, too).
It’s a complex battle, and a good one, forcing the player to make use of several different abilities at once. An excellent test of skill.
Ridley, on the other hand, is a joke. He stands in place and hops up and down, belching a trio of fireballs that bounce up and down along a sine pattern. Like Kraid’s spikes, Ridley’s fireballs deflect missile fire yet can be frozen in place. Unlike Kraid’s spikes, though, the fireballs follow a single path, and the nature of that path is fixed when you enter his chamber.
One fireball path is very tricky to deal with — the flames describe a very dense waveform and stay close to Ridley’s body. The other, however, arcs far away from Ridley himself and leaves a convenient safe spot for Samus to stand at right at Ridley’s feet. If you can get the game to use this pattern (and it resets every time you exit and reenter the room), you can stand directly in front of Ridley and pump him with missiles without taking a scratch or moving a pixel to avoid his attacks.
In any case, your reward for beating each boss is a 75-missile expansion. Theoretically, you can complete the game just by collecting these two expansions along with the mandatory first one, especially since Ridley is quite easy to beat with the Screw Attack. Each boss’ chamber also contains a hidden Energy Tank as a bonus; Samus can only carry a maximum of six expansions, but with these two accounted for there are actually eight in the game.
With these two guys dead, that strange statue room in the northwest corner of Brinstar — you know, up at the top of that long, long shaft — becomes relevant. The statues flicker with energy and, when you shoot them, they rise up to create a passage for Samus to roll through as destructible blocks appear below.
On the other side is a final elevator room — this one far cleaner and more sterile than the others in the game — that leads to the end.