Splatoon was developed and published by one of the biggest publishers in the gaming industry. It had a major marketing campaign, rivalling that of Mario Kart, arguably Nintendos biggest IP.
It was not, however, independently funded and published. Ergo it's not an Indie in any way, shape or form.
Indie is not an indicator of budget or quality. It has a specific meaning that has no bearing on anything you've asked with regards to Splatoon.
Now, do I think Splatoon has a AAA budget? No. Frankly not much besides Zelda has a conventional AAA budget at NIntendo and I don't think they realized what a gem they had on their hands when the project first entered developement.
It was regarded as a playground for younger developers, so it's save to say Nintendo probably didn't allocate a full blown AAA budget to it's developement. Once they realized they had a hit on their hands they gave it an AAA marketing budget though (and cudos to them fo realizing in time and deciding to push it), so in that sense I guess you're right. It was developed, probably on an AA budget but got an AAA marketing campaign.
Also wtf id 'less HD'? Something is either HD or SD. Maybe they have some low res textures in the plaza?







