Tiamat's debut, Sumerian Cry, is a solid album of primitive and arcane Swedish death metal with a subtle early black metal feel at times, and a subtle sense of experimentation.
The production is fairly standard of the metal coming from Sweden at the time, thick and crushing, but not oppressive, with that patented, grinding guitar sound popularized by bands like Entombed. Here though, there's a little more emphasis on atmosphere, giving Sumerian Cry a foggy, 'arcane' quality that works well with what the band is doing.
Although the main focus is squarely on primitive death metal brutality, there are a few interesting, subtle touches that lend Sumerian Cry a lot of character, and hint at the direction Tiamat would go in successive releases. Passages of whispered vocals, acoustic guitar melodies, then there's the odd bit in Evilized where the band breaks into some bluesy 'death n' roll' with a tinkling, tonky tonk piano-sounding melody and some vocal sampling for a moment. Even from the beginning, Tiamat seems to be a band that isn't afraid of experimenting a little, and allowing some quirkiness into the music. During the slower moments of the album, one can hear the beginnings of the doomy direction the band would soon take.