Raw grindcore/death metal, you'll quickly hear some of their influences (such as the REPULSION cover a few songs in). The crowd start to get into it at that point. The polite applause - in marked contrast to the blasting chaos on stage - definitely has a charm though!
XYSMA released two EPs Above the Mind of Morbidity and Fata Morgana before quickly creating a distinct new sound with their albums in the 90s; Yeah and First & Magical being the first two. They've both been reissued, although it's been well over a decade so we might see something soon.