He plays as a striker and has previously represented Portsmouth, Norwich City and Forest Green Rovers.

After leaving Dulwich Hamlet, he moved to Iceland to sign for Thróttur Reykjavík[17] on a one-year contract with an option to extend.

[20] On 24 March 2017, Koroma re-joined Dulwich Hamlet on loan for the remainder of the 2016-17 Isthmian League Premier season, with the signing being funded by the club's 12th Man Scheme.

[21] Following his release by Wealdstone Koroma rejoined Dulwich Hamlet during the 2017–18 season, spending a spell on loan at Carshalton Athletic during which he scored five goals in three games,[22] before returning to the Hamlet and making his third debut for the club, starting in a 1–3 loss away to Enfield Town in the Isthmian League Premier Division on 3 December 2017.

[23] In September 2008, Koroma was called up to the Gambia senior squad for the 2010 FIFA World Cup qualifiers against Liberia and Senegal, making his international debut as a late substitute for Njogu Demba as the Gambian's ran out 3–0 victors.