"Publishers Weekly" thought the book "full of holes, as if its raison d'etre were to set up the action for future books". Like "The Guardian", PW commented on the slow start but noted the pace picked up once the Colony was reached. "School Library Journal" wrote that after a slow start, "the pace picks up", and praised the plot twists and the setting. "Kirkus Reviews" wrote "[d]ense but exciting" and "Booklist" thought "[the novel] appears to be a very promising series kickoff". "The Horn Book Review" felt readers "may lose patience with the slow beginning", but observed that adventure lovers would still like the plot. BBC Audiobooks Ltd. released an unabridged version of "Tunnels" on CD in the UK and Canada on 5 November 2007, and in the United States on 8 November 2007. Reader Jack Davenport garnered critical praise for his "haunting tone" and his ability to depict the people of The Colony with an Irish-sounding accent and their rulers with an "intimidating aristocratic hiss." In the United States, Recorded Books released an unabridged recording on 31 October 2008 read by Stephen Crossley. In February 2013, Relativity Media announced it had assigned Mikael Håfström to direct a film adaptation of the novel. The Polish publishers' website features an interactive game based on "Tunnels".