I love exploration in games. For me this means everything from combinations of ideas as in table top games or epic RTS experiences and challenges.
To huge, abstract, organic maze like expanses of space, often unfortunately thease are not intended but instead as the result of bugs.
To combinations or speeds and track positions at differnt times, as in cirtain racing games. I find particularly the case when the acceleration is low but the top speed is high.
And for me, the enemy of genuine quick thinking, adaption, solving, suspense that almost hurts physically, pondering, storyline you want to experance again and again, real breathtaking graphics, real fear like in Amnesia the Darkest Descent, real learning and self realization, and that you can in the right circumstances learn and train your mind in an hour as you wouldn't otherwise in whole a month.
Is grind, filler, repetition, lack of imagination, replacing the superman avatar with a batman one and releasing it as another game. And as yahtzee puts it, "Mash X to not die.".
Is where there is a stealth game and so a world of intricacy and possibility for staying in the ever changing regions between enities lines and areas of sight, this being before any other mechanics are included, that is spoiled so completly by you having a gun or garrote and being able to run away when seen anyway. Even the parkour game features fighting with policeman, something I've never done in real life parkour and I don't see david beckham getting a machine gun in any football games to enhance the excitement. The reason for all this, in this age of Minecraft, Notch with his numerous of millions of £ and so many other good examples is that gamers like myself apparently don't want it.
I like many others love the game Portal, as well as Portal 2 and Prey. In the developer commentary of portal it is revealed that one room is larger on the inside than the outside, the door being a portal and the inside of the room abstractly existing elsewhere.
Apart from highly free composition of space using modular design, beyond a portal almost as easily being "a new instance of" than just "a teliport to", the film inception also shows an example of where it could be used to stunning effect, with an impossible figure made possible, the enevatable seem in such a figure could using portals be at least somewhat hidden under an arch for example. What's more the mathematics for portals in games seem not just easy using matrices, but similar to how other graphical elements are calculated, also using matrices.
I'm a big fan of the concept of generated content and have some programmatic ideas about how to really make it work, which will probably be saved for another thread.