At first, coming up with a list of favorite PC Engine platformers that don't feature the third wheel in the race of the 16-bit mascots--that would be the "Pithecanthropus Computerus" mentioned in the headline above, who also goes by "PC Genjin" and "Bonk"--seems like a daunting task. After all, when most folks think of NEC's pint-sized system (the Japanese one, at least), the first games that come to mind are Hudson's PC Genjin trio (otherwise known as Bonk's Adventure, Bonk's Revenge and Bonk's Big Adventure in North America).
Think about it for a bit, though, and it becomes apparent that this "little console that could"--because it ably competed with the Genesis/Mega Drive and the SNES/Super Famicom despite the fact that it wasn't a full-fledged 16-bit system--was home to a number of top-shelf run-and-jump (or hop-and-bop) titles.
The five below are my personal favorites. Notice I'm not saying that I think they're the best platformers to grace the PC Engine. Although a couple of them are sure to fit that bill, others are too flawed to be so highly considered. Still, I can't help but like them more than a few of their closer-to-perfect counterparts.
One last thing before I get on with the show, so to speak: I'm not including single-screen platformers--games like Don Doko Don and Parasol Stars--in this post, mainly because they differ pretty substantially from the side-scrolling affairs discussed below.
Bikkuriman World--What a way to start a post like this, eh? I say that because many PC Engine fans likely consider this game's successors, Adventure Island and Dynastic Hero (they're all part of the Wonder Boy series), to be far superior efforts. Although I'd agree with those folks in some respects, I've spent a lot more time playing Bikkuriman World than I have playing either of its follow-ups over the years. I can't really tell you why that is, sadly, although if I had to guess I'd say that it's because I actually like the rather antiquated look--yes, even the Kewpie doll-esque protagonist--and feel of this particular HuCard. Also, I'm a bit of a masochist, which is a must for anyone who wants to tackle this tough-as-nails title.
Mizubaku Daibouken--You certainly don't have to be masochist to enjoy this Taito-made title, which was released outside of Japan as Liquid Kids. That's because this platformer is as cute as can be, what with its bubble-tossing protagonist, adorable enemies (I especially like the ones that look like tottering strawberries) and colorful stages that take players from a lush forest, to (what appears to be) a water-filled cave, to a sandy pyramid. Just because it's cute, though, doesn't mean it's a cake walk. In fact, I've yet to see the end credits of Mizubaku Daibouken--despite spending quite a bit of time with it. My favorite part of this game: Tossing "water bombs" (yeah, I'm not sure what that's supposed to mean either) at anything and everything. Believe me when I say it's addictive.
Obocchama Kun--This Nacmot-published platformer is one weird game. For starters, it's based on an early Yoshinori Kobayashi manga that revolves around a "haughty rich boy during the heyday of Japan's bubble economy." Then there are the little scenes that introduce players to each stage's enemies (all two of them) before tossing them into battle. Obocchama Kun's other oddities include the titular character striking a pose on turtle-shell stages in order to snag power-ups, the bodyguards that occasionally swoop in to protect said protagonist (including a thong-sporting meathead and and an olive-tinged helicopter piloted by a Dostoevsky look-alike) and a series of end-of-level bosses that give new meaning to the word strange (especially the muscular genie who has a pig's snout and literally chokes chickens). Don't worry, Obocchama Kun isn't only a weird game, at least in my opinion; it's also a pretty fun (if challenging) one.
Rainbow Islands--One thing you can say about pretty much all of the games mentioned in this post: They're hardly what you'd call "Super Mario clones." Sure, they're all bright and colorful and feature quirky protagonists who seemingly like nothing more than to leap from one platform to another, but that's where the similarities end. Take Rainbow Islands: Whereas most platformers scroll to the right, this one scrolls upward. Also, this game's main character, Bubby, doesn't jump onto enemies to kill them; instead, he stuns them with rainbows and then leaps onto the rainbows in order to send the baddies to the hereafter. Said rainbows also can be used as stepping stones, by the way--something that not only comes in handy on many an occasion but is darn near required in a few. Anyway, along with all of this rainbow-tossing, there are mammoth bosses to defeat and myriad food items (as well as jewels) to collect. In other words, it may just be the world's best platformer.
Son Son II--Now that I think of it, this NEC Avenue-made title could be placed on the same "is it a platformer or isn't it?" list that includes other PC Engine releases like Marchen Maze, Monster Lair, Shinobi and Valis. It's certainly never felt like a platformer to me; rather, it feels more like a (kind of) cuddly Castlevania spin-off, or something along those lines. Still, there's no shortage of things to jump from and to in this colorful HuCard, so I'm going to consider it a platformer even if it technically isn't. So, what's so great about Son Son II, regardless of whether it's a platformer or not? For me, the main selling point here is that it's about as non-linnear as these games get. Each stage contains countless paths and secrets, and finding and exploring as many of them as possible is at least half the fun of this particular title. What's the other half (or so), you ask? The menacingly adorable graphics, the surprisingly gritty soundtrack and the this-ain't-no-kiddie-game level of difficulty, although not necessarily in that order.
Honorable mentions: Adventure Island (aka Dragon's Curse in North America), Aoi Blink, Jigoku Meguri, Kaizou Choujin Shubibinman 3 and The New Zealand Story.