Rage, of course, has many things that could have been done differently: - invisible walls in some areas. There could be some visible obstacles there to make it more obvious the player should not go there - killed enemies don't leave weapons. The weapon models disappear. - the minor pseudo-RPG thing could have been done a little differently. Why the need to press "enter" so often when "talking" to NPCs? If we'd have dialog options then sure. - the storyline was weak and simply unfinished - static world, physics limited only to ragdolls and two or three crates
There are only two or three areas in the game in which you get instantly shot if you walk a different path than the intended. They're at the begining of the game as some sort of a tutorial.
There are many good things about the game, though: + solid first person shooter gameplay. The last time I had so much fun with a shooter was back in the days of Quake 2 + one of the best ragdoll physics I've seen + diversified maps and enemies. I have not seen any other game like that + level of detail: when you move closer to something you saw in a distance, you don't see the models changing its level of detail or suddenly popping before you. Everything you see is simply there. + when you stop watching the textures too closely, you start to notice they are awesome in overall. So even if Rage might not be considered the best demonstration of virtual textures it's a great future for artists.
The Mod Tools are late... very late. John Carmack complained about it at least a few times on twitter. Tim Willits may be a good lead designer but he's very poor at interviews. It is also the first id game built by a much larger studio. Doom 3 and earlier were developped by like a dozen people. This time, there were around a hundred (or more) - some miscomunication may have occurred and made Tim Willits 100% sure the mod tools would be ready at launch.