I always support making WASD usable instead of arrow keys for those of us who are left handed or having broken arrow keys. Just giving players multiple gameplay options is always nice.
The whole idea of the guards' line of sight increasing as you move is clever, but ultimately broken. Since you can't do a darn thing when you're not moving, they might as well always see that far.
We need to be able to go up through enemies. Constantly being thrown back at the ground because I jumped too quickly and hit a plane I was trying to land on is just annoying.
WE _need_ to be able to run slower and that's all there is to it. It's too easy to miss health and antidotes just because you couldn't slow down or go backwards to get them.
This game needs consistency. Clicking the exact same pixel 20 times produces 20 different results. I often have to try something several times without any change in order to gold the level.