Remain close to keep absorption efficient. The absorption line gets thicker the closer you are to your target. By remaining as close as possible you can absorb them at the maximum rate. The small ring that appears next to your target indicates their health.
Super mode
Survive for 35 seconds and the background will turn white and Super mode will begin. Your orb will begin to absorb every visible enemy, regardless of distance. Note: You are not invincible during Super mode.