Every level will have something special about it, and I am trying to keep the action exciting as the player progress in the level.
I also take a look at different games, to see level design ideas, level structure etc...These give me inspiration.
For example one game I really liked is this one, great graphics, and just looks good:
Action situations, enemy placements, enemy choices etc... a lot of things need to be tuned up and carefully designed to have an exiciting game.
Shadow Gangs is taking the same path.
Above is the Canyons level, still WIP.