Mario 64 to this day is one of the best games its genre has to offer. Its movement mechanics are extremely fluid save for one minor frustration where sometimes Mario will circle 'round his current position when you pull back in the opposite direction instead of just snapping to it, which can sometimes lead to falling off platforms accidentally. Its level design is extremely tight despite how open it is, with everything being compact and interconnected to make for smooth, fluid navigation to points of interest, with interesting objectives pulling you around the maps, with multiple means of getting to most places allowing for creativity to shine through. My only criticism of the level design would be the last handful of levels where they seem to be stretched thin or structured to force the player to repeat things they've already done multiple times over, which can be frustrating. Aside from those minor hiccups though, its one of the greats, for sure.