Level 17

Difficulty

 * You've given 550 sun to start your initial planting.
 * Cats come very fast but up to 4 can be on screen
 * 60 cats is neutral for this level difficulty

Strategy A

 * Start with Give Sunflowers (Or Sunflowers) so you can have some extra sun since cats don't give sun during the night
 * Then plant peashooters in pierce vision (Or without any vision) and wall-nuts to be prepared for the intense battle

Strategy B

 * Just what you do in an onslaught level, you just plant Peashooters and Pierce Shooters. But you won't earn sun.
 * If you chose this way, then don't let the cats scratch your plants, unless you had some sun to plant a wall-nut.