Use your ninja rope and cloaking skills to avoid the enemies, reach the end and take down your ex-boss.
Arrow keys or W-A-S-D to move and jump; click with the mouse to throw a ninja star to kill enemies; click and hold to shoot out a rope you can swing from and climb up with. When hanging from the rope, use the arrow key up or W to climb up, and arrow key down or S to climb down. Use left/right arrow keys, or A/D, to swing each way. You will automatically jump up when you get to the top of your rope. Use this ability to climb up ledges and tall buildings. Press towards a wall when falling to begin a wall slide; then press away from the wall to do a wall jump. Hold the down arrow key or S to enter stealth mode: use you invisibility to sneak past enemies and trip wires. You cannot stealth whilst the alarm is active or when hurt.