SP-wise? Take the enemy AI at least to F.E.A.R. (1) level, that is give them the ability to logically move from cover to cover, avoid obvious deathtraps, and navigate the level to corner the player and attack from different directions without scripting. Learn level design and make something rivaling at least Wolfenstein in "explorability" instead of colon-shaped "cinematic" levels, which are closer to rail shooters. Use 3rd dimension more than putting enemies on balconies. Stop the multiplatform crap and design PC gameplay to be challenging with mouse aiming instead of gamepad joysticks, which make it hard to hit a barn door. Give back the movement speed and lose the eternal slowmo.
It's all been done before, but it's simply a better investment to railroad the gameplay and rely on pumping money in the moving pictures which don't need a creative designer spark.