Three Steak Level 3-11 without clearing any rocks.
You're not left with much room with that restriction, but at least you can use anything. My way is the use one Meteor Magnet, one Telsa Zapper, and the rest Spiked Balls. You can use whatever power-ups you wish, just be sure to use them.


Depending on your placement, you will be left with two tiles: north and south or west and east. Place the Meteor Magnet first, in the west or south side. Place the Tesla Zapper in the corresponding side. This will have the Zapper shock dinos first so the Magnet can hit multiple at once if/when they group up.


Don't forget to collect coconuts; it'll only spawn in the tile you're not occupied.
When it gets to the Dino-splosion, have your power-ups ready. Use them when one's about to run out. Otherwise, most likely, a Pteradon will bypass you.