You have a lot of work to do but thats why you're asking for advice amiright?
I hope you like to read.
First things first, correct me if i'm wrong but i didn't see any wavedashing/wavelanding, but i did see a lot of Rolling. Against your cousins and friends, it may work well, but if you're playing against more experienced smashers, you're gonna get punished the majority of the time, eg) Captain Falcons Side-B. Don't get me wrong though. Ganondorf's roll is one of the best.
Wavelanding is a good method to travel across a stage (a stage with platforms obviously) and wavedashing/dashdancing is also nice to do once and a while to mix up your movements. That's something you might need to learn.
Um, i also saw you use your Nair quite a bit which isn't really a good idea : / Ganondorf's Fair is always you're best choice of approach, and with proper spacing and L-Cancelling, you won't get punished by a shieldgrab. Even a few double Dairs works well. You also use your down-B quite a bit, maybe you should tone it down a bit with the use of your B moves.
Now,to edge guarding, with Ganon, all you combos need to end up with your opponent off the stage. If you manage that, their stock is gone. Ganon has a medley of smexy edge guarding moves that is basically instant kill if you hit your opponent. His Fair is always a good choice, same with his Dair, but they have a slight start up time and it's somewhat risky to use, however his Bair is an excellent choice since it comes out quick and it's like a smash attack in the air. Bair on a recovering opponent = Death. Also, the Uair ...
Uair. Use it moar. It's a great spike to use, especially against characters with no priority recoveries like Captain Falcon, but it works on many other characters with good timing. You basically jump backwards and Uair and the tip of your foot will knock you're opponent just a little bit, but it makes it almost impossible for them to recover, sorta like a shinespike by a fox, and Ganondorf has a pretty good recovery if he isn't getting **** on at the edge. Also, if they're on a platform above you, especially if they flubbed a tech, using a Uair is always a good choice.
Neutral A on the ground is a great move for Ganondorf and it's one of his fastest attacks. Use it to get space and to connect moves to one another. It's basically a cheap chinatown version of the real thing, but it is super helpful. Ganon's F-Tilt works better obviously if they're farther away, and sweeping with the F-Tilt downwards toward the stage can ****. eg)
see here. His Down - B can even spike if you didn't already know. Be creative, the majority of his moves are amazing Edge Guarding moves. Also, something for the lulz, when you see a Sheik about to recover, go up to the edge and space yourself. Imagine if you were to Up-Tilt, you want your foot to land right at the edge. When you see a sheik "poof" up a little bit, use your Up-Tilt. The moment the Sheik reappears at the edge. WABAM. It's hilarious because it actually works with good timing, and oh how knees would be slapped.
L-Canceling. You're not gonna be able to play very effectively with Ganondorf if you can't L-Cancel. I saw you miss your L-Cancel on your Dair a few times which in turn, equals ****. It's very necessary to know how to L-Cancel almost 100% of the time with Ganon.
Ganondorf gets ***** alot. I mean a lot. He's a very large and slow character, and a rush of attacks from a Fox, or even a Young Link can end up being death for you. Ganondorf needs to analyze the situation, and use one of his quick moves, such as U-Air or Neutral A to escape the rush of attacks.
Also, i was too lazy to watch all your matches, but, If you Down-B, you gain an extra Jump and Up-B. It's very useful, even if you're parallel to the stage when you're recovering, chance are, you're going to live. Unless of course, there's someone there waiting for you. You're going to have to learn how Wall tech if you get knocked into the stage. When you're playing better opponents, if they use Falco for example, they're going to try to Dair you at the edge. What you need to learn is to Wall Tech, so you DI towards the stage and you press L or R right before you hit the wall, as if you were doing a normal tech on the ground. This will save you from dieing from a spike. If you're trying to recover and there's a Forwards Smashing Marth, this is going to be something that will be very useful to do. Speaking of DI, thats something you need to work on as well.
And finally, the most important aspect of Ganondorf. If you kill them, taunt.
THRUST YOUR BULGE FORWARD!
Also, you should move this to the
Ganon forums or the
Video Discussion forums