A suspect was arrested on suspicion of assault and released on bail in connection with the incident.
Last Saturday at 11pm, town centre police were called to Peel Square outside Halifax bank following reports of an assault.
A 25-year-old man was taken to Barnsley Hospital with serious head injuries where he remains in a stable but critical condition.
A spokesperson for South Yorkshire Police said: “A 38-year-old man was arrested on suspicion of assault and has been released on police bail.
“A cordon was in place in the area while our officers carried out their enquiries.
“If anyone has any information which might help our officers, call 101 quoting incident number 1129 of October 17.”