Simple hand pattern, complex bass drum pattern! Usually heavy metal grooves have some kind of double kick type rhythm in there, but you can create some very convincing metal grooves with one bass drum pedal! The main thing that creates excitement here is the 32nd note (very fast!) kicks just before the snare backbeat, plus the use of syncopation (kicks playing in between the HiHat pattern). There is a lot going on here but take it bit by bit and you will get it!