Street Fighter's weird new habit of challenging every other even marginally related universe it can find continues in a few weeks with Street Fighter X Tekken, the first of two games to cross over the two series and the one that Capcom developed in-house.

It's a weird game. The previous crossovers have taken two particular routes. The first, the "Vs." series, is a hyperkinetic caffeine-driven lightshow of a game, packed with hundred-hit combos, superjumps, and Ryu nonchalantly generating a laser blast roughly the size of the blast corona on an orbital rocket. Tatsunoko vs. Capcom more or less went this way. The second, the Capcom vs. SNK games, tried for the best of both worlds by making both styles of gameplay available for selection in-game, so it actually could at times feel like the two series were fighting head-to-head.

SFxT, on the other hand, is wedging the Tekken cast into an otherwise-ordinary Street Fighter title, with few nods to where those characters actually came from in the first place. You'll recognize their trademark moves, but they've been effectively reimagined from the ground up as 2-D characters in the Street Fighter engine. If you strip away SFxT's new mechanics, it feels like nothing quite so much as a new iteration of Street Fighter 4.

The plot is pretty much ridiculous, and you don't see any of it unless you play arcade mode with specific two-man teams. A meteor has landed somewhere on Earth, and both of M. Bison's terrorist organization Shadoloo and the Mishima Zaibatsu are racing each other — and the authorities — to get a hold of it. For some reason, anyone who wants to get a piece of this action is going to end up in about half a dozen pitched street brawls before getting anywhere near the meteor, but that's how these things usually work.

Matches in SFxT are two-on-two tag matches, and the first team to get a character KOed loses the round. You can do a hard tag at any time by pushing the two medium attack buttons, or combo into the tag by ending an ordinary hit string — light punch/kick, medium punch/kick, heavy punch/kick — into your character's launcher. This burns off one-third of your super meter, knocks an enemy into the air, and brings in your backup character, who has a narrow window in which to do something horrible to the opponent.

SFxT uses a three-part super meter, which fills via attacking or taking damage, and you can very easily burn off the meter as fast as you can fill it. EX moves, supercharged versions of your standard special attacks, use one-third of the meter, and super attacks burn the whole thing at once. Weirdly, every character can also use a super for "free" by holding down the attack button on one of their special moves — for Ryu, it's his Hadoken — for long enough.

You can spend all three meters on a tag super, where your character lands a canned combo that ends in a flurry of attacks from your off-screen character, or a short-lived beatdown where both characters go on-screen at once. It's a bit like the all-or-nothing nature of the last Mortal Kombat game, where you rarely actually saw supers in high-level play because it was way more useful to hold back the meter for EX moves.

There's also a last-ditch desperation move called Pandora, which can be triggered when your active character is at 25% health or lower. This knocks that character out and brings in your backup, who's rocking a photonegative "evil" look, a full super meter, and a vast power boost. You then have a short window in which to win the match because when Pandora wears off, your character's knocked unconscious.

The strangest feature of SFxT, and the one that's likely to be the most controversial, is the ability to equip gems. These provide your character with a short offensive, defensive, or ability bonus, and each one comes with an activation condition or an associated drawback. Successfully landing three special moves or a normal throw, for example, can trigger a gem that gives you a +10% damage or speed bonus for 20 seconds, and it's available once a round. Another kind of gem permanently adjusts the rules under which your character operates. One lets you automatically escape normal throws, but lowers your damage output by 10%. Another widens the window in which you can link moves together in a combo, but your super meter shrinks by one-third.

I'd initially assumed that gems would be something you earned over the course of play somehow, but in the build of the game I'm playing, there are a few dozen of them available right from the start of the game in a customization menu. You can put up to three at once on a character, with five predetermined loadouts that you can pick after you select your team.

I won't go so far as to say that gems break SFxT, but after playing with them for a few hours, I could see how they'd blow up the game a bit. With the right gems, you can get a slightly weaker Zangief, for example, who's suddenly a combo machine, or provide Asuka with a surprisingly long window of opportunity in which she hits like a freight train. Gems can go a long way toward addressing or mitigating characters' built-in weak points, and there's going to be some kind of world-beating, instantly nerfed gem/character combo about 10 seconds after the game hits retail shelves.

Street Fighter X Tekken is an odd approach to a crossover game. It feels like nothing quite so much as a Street Fighter sequel with a weird selection on the Capcom side of the roster — Poison? Hugo? Rolento? —  and two dozen brand new characters. With the gems, tag combos, and comeback mechanics, it's a bigger, flashier SF4 with a host of new characters to learn. My only true disappointment at this point is that, when I fight Kuma as Zangief, Zangief does not comment on how he finally gets to wrestle a bear on-screen.