Although they are mostly unknown outside of their Polish homeland and the European continent, Toxic Bonkers have been around since the early 1990s, sporadically releasing albums on several tiny indie labels whilst transitioning from their original grindcore-centered template towards a surprisingly varied mix of both modern and longstanding death metal styles.

2007's Progress is the group's fourth long-player in a decade, and its songs are a perfect illustration: never wavering outside the bounds of what one would comfortably define as death metal, yet rarely drinking from the same well twice.

Head-crushing opener "Emptiness" often recalls classic Bolt Thrower with its fluctuating tempo and somber melodies called up from the depths; "Hole in the Head" takes a few Rot & Roll notes from Entombed; the groove-laden "Manifesto" could pass for a Soulfly number; and "Face the Fact" injects dense harmonies reminiscent of Immolation.

On the downside, the numbers on the album's second half don't always establish a strong identity, and the dark horse, "Denial," makes way for some unexpected clean vocals that feel almost like nu-metal, but this album still has more going for it than not -- Progress, indeed.