Sonic the Hedgehog 2/Aquatic Ruin Zone

An ancient ruin located in a forest valley partially submerged in water. For the boss fight two pillars rise out of the ground trapping Sonic between them. Dr. Robotnik flies above them and hammers them, causing arrows to shoot out from them. Robotnik flies too high to be hit by Sonic, you must stand on the arrows and jump from them to hit Robotnik. As the pillars rise from the ground, you can jump on them to reach Robotnik.

If you want an easy win here, stand on one of the platforms as it rises and continuously spin dash into the boss. You'll bounce back on the pillar, ready to do it again and again.