Complex sentence: Simultaneously the band had become popular in Serbia as well and eponymous debut studio album "Goribor" received positive critics and several awards in both Serbia and Croatia, including the webzine Popboks award for the best album in the previous decade.
Split into simpler sentences: Simultaneously the band had become popular in Serbia as well. Their eponymous debut studio album "Goribor" received positive critics and several awards in both Serbia and Croatia, including the webzine Popboks award for the best album in the previous decade.