To be honest I'm not sure this is going to work very well... Randomly selecting games to pit against each other results in, well, this. It's the first round and already we have a platformer from 2002 going up against a party game from 2021. So you can kind of get why this doesn't work already, right? They're two completely different genres with almost two decades of time between them. So really this just turns more into "what game do you like better" than any sort of actual debate. That's why 'Shroomfests are always opposing concepts.
Like, if I were to actually try to participate in a debate on these two topics, it's hard to come up with any solid talking points. Gameplay? Well, these games inherently have vastly different gameplay, so it just loops back around to which one you personally like more rather than necessarily having opinions on why one game does better than the other. Graphics? Superstars is obviously going to blow Sunshine out of the water here, it has a 19-year advantage on it, not to mention three consoles. Story? Well, I'd argue Sunshine wins here, but only because Superstars doesn't have one at all (which it doesn't really need, it's a party game).
Also, 'Shroomfests specifically avoid being based on Mario-related subjects to avoid things getting too heated since this is a Mario community and people are more likely to have strong opinions on things. I'm not saying that you outright can't do a Mario-themed debate, but a bit of food for thought.
for Mario Sunshine and shocked 
for Mario Galaxy
