Easy - Quick to implement
Ok - Not to difficult to implement
Hard - Harder to implement or long to implement
Dash (Easy)
Crouching (Ok)
Sprinting (Easy)
Wall running (Hard)
Grappling hook (Hard)
3D camera clipping through walls fix (Easy)
Deployable walls (ok)
Melee Weapons (Hard)
Projectile weapons(Very hard)
Shotgun (ok)
Flamethrower (ok)
Assault rifle (ok)
Crosshairs (Easy)
Enemy AI (Very hard)
Other mechanics