A man in his 20s was assaulted in the early hours of Friday morning in Montague Street.
He was attacked as he stood sheltering from the rain in the doorway of Poppins at around 3.30am.
Witnesses claim they saw another man approach the victim , who was with a woman at the time, and kick him very hard on his buttocks and then punched him in the face knocking him against the shop door.
He was possibly in fancy dress at the time as he was with a woman dressed as a nurse
The victim is described as in his 20s, 6ft and of medium build. He has short brown hair and was wearing a dark coloured sweatshirt with the sleeves pulled up and jeans.
PC Mark Brett the investigating officer said: “This appears to be a completetly unprovoked violent attack on an innocent member of the public. Police officers arrested the suspect soon after but could not then locate the couple who had walked off. CCTV shows the whole incident and we would urge the couple involved to come forward and contact the police on 101 quoting serial 195 1/11.”
A 29-year-old man from Worthing, was arrested on suspicion of assault. He was questioned and bailed until November 22.
Anyone who witnessed the incident is asked to call 101 quoting serial 195 of 1/11. Alternatively, call the independent charity Crimestoppers anonymously on 0800 555 111.