I've spent the most time in Minecraft so far. Things that really blew my mind:
- Walking up to a block. Feels like it's right in front of you, and they are MUCH larger than you'd think.
- Standing at the base of a tall building and looking up. The sense of scale is incredible.
- Pressing F1 to bring up the GUI (this is cool in itself), and then using the head tracking + mouse click to place blocks.
- Walking down a narrow and low tunnel. It really feels like the walls and ceilings are close.
- Standing in a 1-block deep lake. I found myself keeping my hands high up to keep them out of the water; it really felt like I was standing waist high in water.
Took a while for my brain to adjust to the whole thing, and using the mouse to aim = instant motion sickness. Using simple WASD and head aiming was fine though, just limits your movement. The 'forward' direction should gradually shift towards where you're looking while moving really.
And just generally, the resolution is insanely low, but once your brain gives in and accepts you're actually in the game, you actually stop noticing this so much. Honestly, the whole experience is hard to describe, but revolutionary is probably the best single word I can think of. General tips for hype though: expect the resolution to be horrific. Expect to be a little disappointed at first. But stick with it and there will be a moment where it all just 'clicks' and you're sucked in.