A joke, you say. Why, because they look a little more human? THAT'S what the series played to, making the human-looking deities of Greek Mythology a little more personable by human standards. Don't even bother with that played out excuse of an excuse, because they're still more powerful than what Ryu's faced and/or become due to size alone and still thensome. Kratos has killed two, and with what means he used, he'd kill Ryu MUCH more easily. It's not the fact that they can be killed that makes them weak, it's the fact that Kratos kills them is what shows his true potential and power. Kratos, as the second God of War was already described as more powerful than Ares ever was. Ares, who, with a fraction of his power, reduecd an army of thousands upon thousands of men into a field of broken, burned, torn, overall mutilated bodies. I'll say it again, the only thing that's killed a God in the God of War games is that which also held the same kind of Godly powers. The only "Gods" Ryu's ever killed are no longer even in NG canon.
Kratos' chains go farther than ever in a few Chains of Olympus videos, grabbing the Basilisk atop a bridge gate from practically the other side of the bridge. His best spells cover practically that much and are instantly activated, during which times Kratos is often untouchable, much less vulnerable.
It deflected much more than basic projectiles. The Golden Fleece has blocked fireballs, waves of varying energies lethal and non-lethal, Gorgon rays, Zeus' thunderbolts, and thensome. Those go beyond basic material projectiles, and Ryu's ninpo lies somewhere in that overall list.
That's completey underrating Kratos' abilities to ignorant proportions. Kratos' reactions allow him to dodge thunderbolts and a charging Zeus (who dashed at speeds no slower). Yeah, Kratos swings chained blades, with the effectiveness to defeat the likes of every man, beast, mythical being, etc. that came his way, skewering/vinesecting/mutilating them while spinning them around like helicopter propellers. He also uses them as literal arm extentions for out-of-range objects, to scale walls and ceilings, to swing like Spiderman from anything the blades can latch onto, etc (or break the Basilisk's jaw like King Kong did to that V-Rex). That's versatility, much moreso than what even Ryu's main ninja arsenal. Kratos uses every single weapon he gets his hands on just as efficiently as Ryu does, only not as elegantly, due solely to the game's main approach at brutal combat, but elegance and finesse =/= superior, Kratos proves that. God Kratos, I don't want to bring up since it's just plain not fair in this debate; all God Kratos needs to do is make a quick gesture, and Ryu's head explodes while his corpse is set aflame.
Kratos has never ONCE was shown to tire after just ONE battle without something that would leave Ryu dead. It took a series of battles to Tartarus and back to do that (THAT'S a good example, better than what you gave, and even then, that's when Kratos was still at his most...expendable). Kratos was only on the back of the Pegasus for like a tenth of the game, all the while slicing apart clusters of harpies, jumping off of the Pagasus' back to lay waste to an armada of Griffins piloted by the legionnares of the Sisters of Fate. Anything where sex or rest was involved was only in the beginning of the game(s). Hell the second time, it was in the MIDDLE of a battle with the Colossus of Rhodes, who occasionally ambushed Kratos, for example, when it to crush Kratos under its foot (at which point Kratos tossed it on its ass). Put Ryu in that situation, he'll be lucky to see the foot coming, much less stop the attack in its tracks. It's not BS to say Kratos has more stamina when Kratos goes through twice what Ryu does (that's being lenient) and comes out of it unscathed. So seriously, you used a bad example because Ryu would be even luckier to so much as survive at least one of the Colossus' ambushes than Kratos was to survive being slammed by it's massive hand when it fell at a gaining momentum.
Skill-Ryu
Load o' crap. Kratos takes things twice the ferocity of most of Ryu's boss enemies and crushes them with whatever he sees as usable, be it his bare hands, a weapon, or body part. Ryu may have twice the finesse acrobatics of the Prince of Persia (quite posibly more than that), but Kratos has infintely more brutality, tenacity, and raw power. Ryu's pretty strict on the belief that it's his training that made him the "Super Ninja" that he is. I'm not in the position to prove him wrong, he's beyond any ordinary human, but Kratos is far from that, in terms of both biological heritage, and power. He can take anything Ryu had thrown at him only in a more grisly fashion.
Speed- Ryu
Concedable at the least. In terms of overall speed, most of Kratos' lies in attacks (with his blades), while Ryu's got nimble movements.
Spiritual energy/energy-Ryu
That's something that doesn't even apply to Kratos. No comment
Magic-ryu
EPIC LMATHAF***O. Hate to say it, but Ryu's ninpo doesn't have two sh!ts on Kratos' divine spells. Not because they're enhanced with the divinity of the Gods, but because not only are Kratos' magic powers faster to the attack, but as a whole his best ones cover more ground by basic standards, and leave him invulnerable for the duration. One casting of Poseidon's Rage, and Ryu's fried (literally). It has properties fairly similar to Ryu's Art of the Izuma, only on a clearly larger scale and thensome. That's just an example.
Weapons-Ryu
Numerically, but no further than that. Like I said earlier, Kratos' main weapons alone are five of Ryu's or Dante's weapons, and in terms of power, the Blade of Olympus is able to not only absorb power of any kind, but already currently contains Kratos' powers as the God of War.
Strength-Kratos
And against the likes of Ryu, it's all he'll need if Ryu gets in close (which Kratos can make happen on his own).
Range on all grounds-Ryu even though Kratos might edge out mid range
Not a thing goes to Ryu in range, esecially when Kratos' Blades of Chaos/Athena's Blades cover more ground than what any of Ryu's main weapons do (and, at their fastest, can extend from his hands almost instantly). That's not even counting the likes of Kratos' spells, or other weapons.
Even if more physical attributes go to Ryu as a generalization, that doesn't mean it'll instantly help him succeed, because none of it is really at THAT high a caliber. Higher than any normal human, yes, but not as high as those with more than just human blood.
Ryu, in the end, isn't really all THAT powerful. He's not as fast as Dante, nor as strong as Kratos, his projectiles are completely ineffective against either one (who not only have superior projectiles, but also means to defend against anyone elses', Ryu's included), and both have the ability to assume a more powerful form in battle, which would just be overkill against almost anyone but eachother. Ryu's beyond the likes of the Prince of Persia, and probably Heavenly Sword's Nariko, but in the world of Action Genre protagonists, that's about it. Kratos and Dante are nigh omnipotent at full power and are the only ones of anyone stated here who would put up a fight against one another.
Hell, even if by some chance that Kratos is at too much of a disadvantage, all he needs then is to "Let the Rage of the Gods/Titans drive [his] blades". Ryu has no power of the sort, much less a chance against it. Another little "category" in which ensures Kratos' victory. But like I said, it's just overkill against someone like Ryu. Speed is the only physical category where Ryu ISN'T beat when compared to Kratos, and it's FAR from enough. All things taken into acount, Ryu would be more of an annoyance for Kratos than an opponent.