I recently played some of Valve's Orange Box games, and I noticed something. Portal has a complex mechanic but mostly very graphically simple levels, i.e. fairly stark and austere with little clutter. Half Life 2 has a more traditional FPS mechanic, but aims for realistic graphics. When I compared the two games I found that Portal was in fact much easier to pick up and I got stuck in it a lot less. I guess my number one observation on this is that in many cases Half Life 2 became like a hidden object game. There was clutter everywhere, e.g. cardboard boxes, soda cans, damaged walls and floors. It's realistic... that's the way the world is. But it made it very challenging to spot the things you're actually meant to pick up and use. And in a similar vein, you can see areas that you can't actually get to (or maybe just much later in the game). I found myself wasting time exploring things that were dead ends but didn't look that way. And don't get me started on the atmospherically lit (e.g. pitch black) stairs that I needed 3 tries to get up while being chased! In Portal however, virtually everything you could see was required to complete the level. In addition there was an iconic quality to objects. Once you'd seen a button you knew what all buttons looked like. And even if you hadn't seen one before, the form suggested the purpose (no, not just for buttons). I also really liked that they didn't hide that certain gameplay was linear. The circuits, ticks and crosses, etc made it clear how you'd know when you'd completed a level. At the end of the day I have great respect for the graphics, physics and atmosphere of both these games. However I feel that the design of Portal cleverly used the design and story to cover up any technical limitations, which is what I hope for both in games and in movie special effects. Has anyone had similar gameplay experiences, or encountered good techniques to avoid such problems? Not just in 3D games, that's just my examples.