No, although in this day and day age you're almost right since AA releases largely died last gen. AAA games are about the amount of money thrown at it, both production and marketings. Its nothing we know for sure but in many instances its something easily gauged.
Batman Arkham Knight: AAA
Lords of Fallen: AA
Its of course respective to the times and I guess the genre. Mario Galaxy would be consider a AAA for its its environment, so would the new Ratchet and Clank Remake.
AAA action game >>>> AAA platformer
Naturally the term has also evolved to reflect our expectations of games. So if a game is huge in scale, impressive in graphics and ambition we'd tend to note that as AAA as for the longest time such things are typically tied to budget, although thats not always the case. We also tend to class things with huge potential to sell as AAA, but again its like the summer blockbuster thing: movies of big budgets, fancy effects and big actors are likely to sell more tickets. The meaning of the word feels quite loaded at times but it all comes back down to budget and 9/10, I think people are getting it right.
Demon Souls: AA
Dark Souls 2: AAA (if not from production then from marketing)







