South Park Tenormans Revenge

Achieved after completing the level "...Best Served Chili"
Story related, cannot be missed.

Here are some general tips for the game:

• There are a couple of items throughout the levels that you can pick up to help you out: Hearts for an extra life, Cheesy Poofs for 1UP, Snacky S'mores for full health, shields to make you temporarily invulnerable and the yellow sticks to slow down time.
• Kill mice for an extra life.
• If you have trouble surviving, try using Kenny and Kyle the most. Press to change character during a level.
  Kyle's ability to remove forcefields and disable robots temporarily is great for tight situations. His alter-ego, The Human Kite, is also useful because he can glide over enemies and obstacles.
  Kenny can jump over enemies and obstacles with his high jump skill. His alter-ego, Mysterion, is great when he is a ghost because he's invulnerable and every enemy he touches dies.
• Avoid enemies if you're not going for a gold medal, except for regular ginger robots when you need a heart.
• Choose your kills wisely when using the weapons, as they break rather easily.
• Run past orange portals, they spawn new enemies if you kill the existing ones.