So I see you's doing ROB now? I really can't believe how many people are doom and gloom over this matchup, because I don't think it's that bad at all. Granted I've only faced about 3 ROB players ever, but judging from my ease in fighting them, I'd say that this is a matchup that Ganon doesn't have that much difficulty at all. Let me explain:
Approaching- ROB doesn't approach. Ever. Ever. If you see a ROB approach you, spam Warlock Punches because the likelihood of landing one is about the same as the likelihood that you find a ROB that approaches. Seriously, though, Ganondorf is going to do some major hustling to get to ROB because of its laser beam and gyro.
- Uncharged beams tend to get off a little faster than fully charged ones, so look at its head to find how charged the laser is. Spotdodging or airdodging (foward) the laser are your best bets.
- Now for gyros. Always shield them unless there is an attack that goes through them (dash attack, I think?). If you get between ROB and a gyro, keep extra-special attention to your spacing because he's just going to tilt you into that gyro all day long. If ROB is holding a gyro, camp him, dodge the lasers, and force him to throw the gyro. You can't afford to be worried about facing ROB's defenses while a gyro is coming straight down for you from the sky.
Short points: Dodge the lasers, shield the gyros, be cautious when ROB is holding a gyro.
Close Combat- ROB has a very good foward tilt and a great trip-tastic down tilt. In the air, ROB's back-air comes out very, very quick, has a sourspot, and gives it momentum away from you. Ganondorf has three types of grabs, a great down tilt, and the tip-man plus a good back air if he needs to use aerials close to the ground. Thunderstorming is awesome in this battle. My best suggestion for fighting ROB on the ground is to space with down-tilts, use short-hopped flame chokes if you think it's going to shield, and keep it honest with back airs and full-hopped neutral airs; thunderstorm works when you're both really close to each other.
- ROB's spotdodge to downsmash deserves its own section. You will see it a lot. It's ROB's favorite thing to do out of a spotdodge. What do you do against it? If he's facing you, wait for the spotdodge animation to run out (get a feel for the noise it makes) and spotdodge right afterwards. If it used down-smash, you get a free grab if you're close enough. I guess what it doesn't stop is ROB's neutral air and down-tilt spams, in which you could try other methods. If ROB's back is facing you, shield. That way you can guard either its down-smash, back-air or neutral air., whatever its style of use is.
Short points- Maintain your distance and stop freaking out about spotdodge-downsmash.
Aerial Combat- You don't want to be over ROB. ROB's up-air comes out fast and is a multi-hit adventure, and its foward air comes out quickly and can chain with itself at low percents. Luckily, Ganon's up-air outranges ROB's foward-air, so if you see ROB coming straight at you, up-air and make sure that it doesn't get close to you. If ROB's back is facing you, you know you're facing either a back-air or a neutral air, so DI away from it and airdodge because you are not getting through that fire. Remember that Ganon's neutral air comes out very quickly, so if ROB is trying to chain you, use it and get yourself out of there.
The best place to be is in front of and slightly below ROB. ROB can't do anything about it and you can up-air or even foward-air to your hearts content.
Off-stage- ROB can do anything offstage. Watch yourself when you're using aerials to recover because you will get hit in the face with a laser/gyro if you're not careful. When you're recovering, see what angle ROB is trying to get to you and dodge/attack accordingly. Sadly, ROB's boosters make WTFPWNSOME spikes impossible when ROB's recovering.
Verdict- The best news for you is that ROB generally cannot follow up its attacks with squat. Most stuff it does sends you away to the point where ROB can't get a string of attacks together. This then comes down to a war of attrition. Your powerful attacks are going to kill him earlier than its used to, which is excellent because you can't afford to not send him into the KO zone when it has that crazy recovery. If Ganondorf gains enough momentum, nothing that ROB has can quench that fire, so do whatever you can.
Dodge lasers, shield gyros, watch out when ROB spotdodges, don't do anything stupid off-stage and keep it cool. Remember, ROB is a camper, but one of the most reliable ways to stop a camper is with a tank.
FINAL SCORE 55-45 ROB, although I'm leaning more on 50-50. Ganondorf's punishment game is much more dangerous than anything ROB can put out. It's just a matter on if Ganon can breach the projectile defense system.