I think one big difference is that we have the internet now, with wikis, Game FAQs, youtube walkthroughs, etc. I played Super Metroid using a walkthrough, and t

I think one big difference is that we have the internet now, with wikis, Game FAQs, youtube walkthroughs, etc. I played Super Metroid using a walkthrough, and that completely breaks the illusion of exploration, because it's then clear to the player that the game is linear and there is always only one way you can go. (Metroid 1 holds up better in that situation, because it actually gives the player genuine choice about what order to do the different challenges). The most popular game right now is probably Minecraft. Note how it exactly takes advantage of this environment: in order to have fun in it, you want to read tutorials about how to build various stuff.