In today's gaming landscape, you'll be very hard-pressed to find a developer making a game with content that doesn't have every inch of its code thrown in your face.
Think of the difference between something like the Witcher series (where a choice in the second one cut out a massive portion of the game), versus Batman: Arkham Knight, where to get the true ending you literally have to mop up the entirety of Gotham's villains, alongside all 315 Riddler Trophies.
It makes sense for a studio to get everything out there and let the millions of gamers worldwide lap it all up, but all the same, if you can design a world we want to explore - and one that can hold things back for repeat playthroughs and future discoveries well, that's mighty special indeed.
10. Metal Gear Solid 3: Snake Eater - 'Guy Savage'
Kojima's third instalment in the three-dimensional MGS saga remains his finest after the first, and one that despite some of the weirdest characters put to code (a man made of bees, anyone?) has the most varied gameplay, most coherent story since MGS 1 - and some of the coolest secrets. One particular highlight is this weird, sepia-toned hack n' slash level that puts you in the shoes of a very mysterious hook-handed zombie killer. Directed by fellow Konami-whizz Shuyo Murata (in a move that would impress Hideo Kojima so much he'd then be allowed to helm MGS 4), codename-level Guy Savage is only available if you load your save at just the right moment. Coming after Snake has been captured and imprisoned, most of us were dying to see what happened next - and as such launched straight into escaping the facility and barreling on with the story. However, if you save your game here, quit out and load it back up you'll get booted into the dream level, where you'll have a good five minutes to decapitate as many foes as possible. In an interesting note, this was initially meant to be a full game before budgetary and/or time constraints got in the way, and although Kojima initially wanted to include his own game, Gradius, as the bonus, instead this incredibly well-designed secret turned out far better.
