Recorded entirely within the month of February 2021, the album is Keller's response to the RPM Challenge, an annual challenge to create an album in one month. During its creation, Keller shared 2 minutes of new music every day on his blog, and asked fans to comment and make suggestions for the following day. Shimmer contains some of Keller's most propulsive tracks, bubbling with analog beats while also deploying a multitude of motifs that mesh like clockwork. The more meditative moments (as on the title track) show off his compositional knack for beautiful, neoclassical melodies.