The more I play (sweeping up those last stars, stamps and flags for
the more I love and appreciate the game. I loved it from the very beginning, but was ever so slightly disappointed in the game and how fast I was going through it. The further you get, you realize the insane variation the game offers (almost everything is unique from level to level, it's quite amazing). It's also ridiculously replayable, the levels are so well designed you could replay them in different ways forever (sp/exploring, sp/speedrunning, mp/explore, mp/speedrun).
It already surpassed Galaxy 2 for me, let's see if it can achieve God-Tier status, it's getting mighty close now. It just feels like this is pure, unadultered Mario goodness. As much as I love and even prefer the more open adventurous style Mario's like 64; as a pure platformer, this one probably takes the cake as being the best representation of what Mario truly is. The pure essence if you will.