Road Runner's Death Valley Rally/Zippity Splat boss
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The first boss level.
Boss: Catapult
The blueprints show that there's a weak point at the front of the catapult. Don't go too fast up the platforms because under the catapult is a bunch of spiky bushes which will damage you for 1 point. Rocks thrown by the catapult will damage you for one point. The spiky part of the catapult will damage you for two points.
Get in front of the catapult, and peck away. If you get there just when it's throwing a boulder, keep pecking for a few seconds, and when you see the catapult go to throw another, hit left and tap the turbo button to get away from it. You may hit a rock but 1 damage is better than 2.