In general, Mario should be:
- Staying out of range of Snake's moves (especially ftilt and utilt)
- Getting in range for his own moves to land
- Performing combos at low percents to build damage
- Killing with gimps (especially using the cape) and smash attacks
- Catching and rethrowing grenades, and caping them (Snake can nade strip which makes this harder)
- Remembering and avoiding C4s and landmines
Detailed analysis:
0:13 -
What happened: Mario spawns and immediately runs forward off the platform to the center of the stage.
What he should have done: Mario is better off playing a little more campy to start with. He should be shooting fireballs, and either staying on the right platform, jumping to the top platform, or running backwards off the platform to the stage.
0:14 -
What happened: Mario jumps and performs a uair, landing on the left platform where Snake spawned. However, by now Snake has dropped through the platform and pulled 2 grenades.
What he should have done: This is an example of attacking where the opponent was, not where they will be. Snake could utilt, uair, or just shield and wait for the nades to explode. Mario could have dash grabbed Snake under the platform, short hop uaired under the platform, or stood and waited, because Snakes own nades put pressure on himself.
0:15 -
What happened: Mario realizes his error and runs off the platform, using a bair to put pressure underneath the platform where Snake was. However, by now Snake has rolled to the center of the stage and Mario has accidentally landed right on top of him. Snake sees Mario coming towards him and shields out of his roll, powershielding Mario's bair pretty much by accident.
What he should have done: Standing on a platform above Snake is dangerous. Usually the safest options are to full hop or double jump away (perhaps up to the top platform). Running off the edge the way he did is alright, but Snake could have punished him by waiting for the bair and ftilting or by picking up and throwing one of the nades.
0:16 -
What happened: Mario's bair wasn't autocanceled, but it doesn't have much cooldown anyway. Mario knows that after powershielding, a lot of players will drop shield and try to attack or shield grab, so Mario uses his fast jab to punish that option. He uses all 3 parts of his jab combo, all of which connect and the knockback sends Snake out of Mario's range, and to the very edge of Snake's ftilt range.
What he should have done: Mario could have grabbed, or done one or two jabs and then a different move (such as grab or ftilt) to do more damage. However, doing the full jab wasn't a bad option.
0:17 -
What happened: Mario short hop fireballs while advancing. He lands behind where Snake was and tries to jab interrupt (probably buffered) in case anything happens. Meanwhile, Snake does both parts of ftilt and gets hit with the fireball during the second part. After getting hit and Mario jumping behind him, he shields.
What he should have done: Standing just outside of Snake's ftilt range is a very delicate position for most characters. Many Snake players will ftilt, relying on its speed to avoid punishment for whiffing. Better Snakes might walk forward slightly and then ftilt, which is almost as fast and would put a lot of pressure on Mario. Short hop fireball is not a bad option, but Mario probably should have moved back slightly while doing it, instead of moving far forward. Another option would be to walk forward and shield, waiting for the ftilts with the intent to shield grab, or walk back. Snake also could have used his DACUS, which makes being on the ground anywhere in front of him risky. Short hop dair, short hop uair, and empty short hop are other potential options.
This is just the first 5 seconds of the match. The rest is left as an exercise to the player