I suppose that killing is acceptable for me, but when it's the main thing in a game, I dislike it. I still enjoyed Half-Life 2 but that was due to atmosphere, sound, and story. I like to use my brain, not my reflexes. Plus, I'm completely non-aggressive.
I'd like to see more innovation and creativity in games. Art games. Imaginative games. Games that take me away from the norm and change everything. Games that make me cry. Katamari Damacy, Ico, Spore, Grim Fandango, LittleBigWorld, Fahrenheit, Shadow of the Colossus, Dreamfall: The Longest Journey, Psychonauts..
Every level of Psychonauts was a trip into another person's mind. God, it was amazing. You collect figments of their imagination and emotional baggage. It's as hilarious as it is insightful. I cannot recommend this highly enough for anyone who is interested in different personalities or psychology. A paranoia level where you're running through a warped suburban neighborhood where shady cloaked figures are disguised as road workers and gardeners? A level where you hop into a game of chess to play against an imaginary Napoleon Bonaparte, and you have to recruit all of the pieces? There's a Bi-polar level that takes place in a theater, and the entire set changes when you throw a different light on it(manic or depressive). There's even a level that I would consider INTP: a very, very, organized mind in the shape of a cube.
I want more stuff like that. I want more Tim Schafer and Ragnar Tornquist games.. and I want Brutal Legend and The Secret World to come out already!