There's clearly a lot of experience point-sparring there. It's not just in the fact that you're only throwing the kicks, its in the general attitude of throwing the kicks and then walking away. It's in the dancing and dropping the hands while well out of range, and staying well out of range, moving in briefly, and then way out of range again. It's an approach that we see very rarely in MMA, because it's very difficult to make work against people who are good inside fighters, whether grapplers or boxers, because they will wait and use their counterpunches or the clinch.
I don't really like the backyard thing, so that definitely leaves a bad taste in my mouth, generally. I'm not gonna lecture you, since I'm sure you have a reasonable understanding of the risks involved. I'm a young guy and like just throwing down with friends as much as the next guy. Just keep them in mind when you don't have a referee or a coach around to keep an eye on your safety.
If you want a lengthy critique of your grappling, I'm happy to do that. You posted in the standup technique thread, and you're clearly a guy who cares more about his striking than mat work, but I will say that both guys have a long way to go on the ground. There are several serious mistakes in the ground work where both guys had attempts to end the fight with simple submissions and couldn't make anything happen.
I'm a broken record on this stuff, and the guys around the grappling section know this: it's the little things in jiu-jitsu. If you're going to go for a guillotine, lock your guard up high, in the armpits and crank down with the legs. If you're going to use of the half-guard, secure the position, get the underhook and attempt to keep your opponent close instead of letting him stand out to pass. Don't just throw legs up randomly and hope to land an upkick. Apart from being very dangerous, a competent grappler will either (if he's nice and trying to work a game) pass or (if he's feeling cocky) attack your leg and possibly put you in a really dangerous (from a health standpoint as well as a technical one; even more so out in the backyard) spot.
EDIT: I will echo Intermission, just for the purpose of clarity. It really is a bad idea to fight in a backyard like this. I hate the Kimbo Slice style stuff, and I deal with enough tough guys who think that they are the UFC-bound on the basis of a few backyard brawls. It causes more serious injuries, from what I've seen, than supervised sparring sessions, because of the lack of headgear and general supervision. I strongly recommend joining a gym, where you have the opportunity to train both with people who can give you tips while you're training and who can make sure that you don't do anything to seriously injure yourself.