Friday Night Funkin vs Rex introduces Rex – an evil robot original character (OC) the creator has been developing since second grade. This free online FNF mod is set in Week 6 and features three unique songs: helda, foren, and forther. Battle against Rex in a rhythm showdown that tests your timing and reflexes.
For the best performance, the creator recommends using the Turbowarp version: https://turbowarp.org/511366395. The description sums up the gameplay perfectly: "It's basically like DDR, press arrow when arrow over other arrow. And uhhh don't lose."