It's not just about performing the mitzvah, it's also about the attitude that goes along with it. G-d wants your heart. He doesn’t need your mitzvos, but he is giving you an opportunity to get closer to Him through His commandments. Mitzvos aren’t meant to be done by rote, but rather with feeling, like you would do things for people that you love.
In this video, Rabbi Siddur explains why it's important to do mitzvos with joy and zrizus (alacrity). He takes you to an amusement park, a ski slope, a construction site and a gym to show you how you can defy the limitations of this world and become a more spiritual being.