The purpose of the game is to connect the most pairs of bugs of the same color to gain score. You have to click, aim and release. Gotta be accurate to calculate the other bug's speed to not fail the shot. The quicker and accurate you are the higher the score.
Btw, the idea of ladybugs mixed with spiders might be kinda crazy but couldn't imagine other way on how can ladybugs connect with other ones, and spiders were to thin to click on, plus... who cares?