The most familiar example of arcade sideways walking is Altered Beast. If you recognize this Genesis and arcade "classic", you're probably already on board and ready to move to the next lesson. If not, check it out, and remember, kids: never "wise fwom youw gwave" without adult supervision.
The idea here is that we have a flat 2D side-scroller with extremely basic environments and swarming enemies. Observe the light platforming, the monotonous enemies, and the steady environmental progression (it's NOT a series of static fights). I used to think of these games as flattened beat-em-ups (Streets of Rage condensed to a single horizontal plane), though it never felt correct - now I'm going to attempt to explore the empirical backing that proves that feeling correct. The ASW is, in fact, almost completely unrelated to the beat-'em-up.
The one particularly interesting feature introduced in a handful of these ASWs will be familiar to most from Secret of Mana (and this blog post about it). The auto-charge meter, whereby pausing between attacks slowly powers them up. Here's an example from Astyanax:
Watch the "PW" meter at the bottomAs fast-paced actioners with a constant stream of enemies, the meter serves ASWs (among them Magic Sword and The Legendary Axe) completely differently than it does Mana. It actually becomes a primitive combo system, allowing for fast, weak strings of hits to be alternated with slower, more deliberate blows. If the animations were to reflect the attack power, this would be almost immediately recognizable as the same timing-based combo system used in modern 3D action, seen in the likes of Bayonetta and Darksiders.
ASWs are, for lack of a better word, not all that fun. They're primitive beyond their time - platformers, by comparison, were fully evolved (in the Pokemon sense) by the early '90s. Unsurprisingly, they vanished as quickly as they appeared - their life-cycle seems to have terminated in tandem with that of the arcade itself. Other arcade-birthed genres like the shoot-'em-up and the beat-'em-up endured consolification and live on in one form or another to this day. The ASW appears to have gone the way of the dodo.
BUT DID IT REALLY? Oooh, this twist is gonna blow your mind. See, here we've got a regular Charles Darwin on our hands. Did you think all the evolutionary imagery (the one word worth of it) was going to be a build-up to a Beagle joke? No, I want to talk about whether God based video games on humans which were based on monkeys, or if it was all here in the first place.
In 2001, the sixth console generation was unleashed (that's the one with PS2/GCN/Xbox). This new era brought with it a whole new style of gameplay, one destined to [rule them all]: the button-mashing 3D melee action combat thing. Yeah, it doesn't have a good name, because these games tend to be classed elsewhere, most frequently as action/adventure. What I mean is Devil May Cry, God of War, Ninja Gaiden, etc. Think for a second: where did they come from? What is a PlayStation, N64, or PC precursor to this style of play? What early 3D game pitted a single combo-equipped fighter against mobs of weak, varied enemies? Sure, 3D fighters like Virtua Fighter and Soul Edge existed, as did the more RPG slanted action/adventures (Ocarina of Time, Castlevania 64), but the former had yet to be injected into the latter. Complex play control was reserved for one-on-one matches, while group-fighting was the territory of brawlers, RTSs, and RPGs. So was DMC the first game to pair ongoing battle with linear adventuring?
Ostensibly, yes. Wait, that's the second time I segued paragraphs by posing a question in one and answering it in the next. Whoops. Strictly looking at content, ASWs have an almost uncanny degree of commonality with sixth- and seventh-gen melee action games. Historically speaking, the answer is far murkier. What we have, in fact, is a case of "the missing link". The chain of influence is unlikely to have skipped ten years and two generations - I doubt RE4 morphed into DMC after the design team spent a long weekend playing through Legendary Axe. But Golem and I have struggled to brainstorm even a single game that bridges the gap. So be on the lookout! It could be out there.
Until then, I'm gonna spend the next week or so rigidly classifying the action combat genre in contrast to the brawler.