The 27-year-old captained the side to win their first major trophy since 2016, while also qualifying for the UEFA Europa Conference League.
Having drawn goalless after regulation and extra time, Sliema Wanderers were decisive in the ensuing shootout to triumph 4-2 on penalties.
Maltese international goalkeeper Rashed Al-Tumi was the hero of the day after saving two penalties from the Floriana players.
Meanwhile, the FA Cup is Acheampongâs first major trophy since joining Sliema Wanderers from fellow Maltese side Mosta FC last year.
The defensive midfielder came through the Right to Dream Academy in Ghana, although he has mostly plied his trade abroad in his professional career.
Acheampong played college football in the United States before joining French Ligue 1 side Bastia in the summer of 2016.
He went on to have stints with MLS club LA Galaxy, Mexican side Veracruz and Finnish side AC Kajaani.
The midfielder returned to the Ghana Premier League briefly when he signed for Elmina Sharks as a free agent in 2021 but spent just four months with the club before securing another move abroad.
Acheampong, who has been voted into the Maltese Premier League team of the season, is yet to be capped by the Black Stars although he has previously been called to the U20 squad.