I think that the confusion arises from the fact that the French colonial possessions were administered by the Navy during the 1700s. As the Wiki article to which coopman directed us, the French navy was termed "Marine Royale."
Many of the French troops at Savannah in October 1779 were colonial units, thus were probably termed "marins" which the game designers, not understanding the term, translated as marines.
The French order of battle for the assault on 9 October 1779 (from Davis K. Wilson's excellent book, The Southern Strategy: Britain's Conquest of South Carolina and Georgia, 1775-1780, is:
French Forces (Gen. Le Comte d'Estaing)
Avant-Garde of the Army (Col. Jules Bethis)
Volunteer Grenadier Company (Capt. Aubery) -- 60 men
Volunteer Grenadier Company (Capt. Herneville) -- 60 men
Volunteer Grenadier Company (Capt. De Veone) -- 60 men
Grenadier Company of Armagnac -- 49 men
Chasseur Company of Armagnac -- 53 men
Grenadier Company of Agenois -- 73 men
Chasseur Company of Gatinois -- 80 men
[My supposition is that the first three are colonial "marins" while the last four are regulars.]
Right Column (Comte Arthur Dillon)
Avant-Garde
Volunteer Grenadier Company (Cpat Moedermotte) -- 60 men [probably colonial "marins"]
Battalion of Grenadiers
Grenadier Company of Auxerrois -- 57 men
Grenadier Company of Foix -- 83 men
Grenadier Company of Dillon -- 94 men
Grenadier Company of Guadeloupe -- 50 men
Chasseur Company of Guadeloupe -- 51 men
[My supposition is latter two are probably colonial "marins" and rest are regulars.]
Battalion of Grenadiers and Chasseurs
Grenadier Company of Cambresis -- 88 men
Grenadier Company of Haynault -- 85 men
Chasseur Company of Champagne -- 67 men
Chasseur Company of Le Cap -- 50 men
Chasseur Company of Port au Prince -- 47
Dragoons of Conde and Belzunce -- 30 men (dismounted)
[My supposition is the last two chasseur companies are colonial "marins" and rest are regulars.]
Left Column (Baron de Steding)
Regiment of Fusiliers [line infantry]
Fusilier Company of Armagnac -- 175 men
Fusilier Company of Auxerrois -- 1434 men
Fusilier Company of Foix -- 203 men
Fusilier Company of Dillon -- 256 men
Fusilier Company of Walsh -- 26 men
[All from regular regiments.]
Regiment of Fusiliers [line infantry]
Fusilier Company of Cmabresis -- 94 men
Fusilier Company of Haynault -- 208 men
Fusilier Company of Le Cap -- 47 men
Fusilier Company of Guadeloupe -- 135 men
Fusilier Company of Port au Prince -- 87 men
Dragoons of Conde and Belzunce -- 23 men (dismounted)
[My supposition is last three fusilier companies are colonial "marins" and rest are regulars.]
Reserve Column (Gen Le Vicomte Louis Marie de Noailles)
Corps de Reserve (drawn from first two columns) -- 400
Artillerymen (field pieces, 6-lbr) -- 60 with 2 guns
Troops Remaining Entrenched (Maj Jean-Claude-Louis de Sablieres
Volunteer Chasseurs (mulatto) of San Domingo -- 540 men
Volunteer Grenadiers (mulatto) of San Domingo (Maj Des Francais) -- 66 men
Royal Corps of Marines -- 337 [Probably actual "marines" from warships.]
Chasseur Company of Martinique -- 52 men
Fusilier Company of Martinique -- 36 men
Dragoons of Conde and Belzunce (M. Dejean) -- 20 men
Gunners and Cannoneers -- 163
Troops Remaining in the Batteries
Right Battery
Royal Corps of Marines -- 108 men
Cannons (18-lbr) -- 5
Cannons (12-lbr) -- 11
Left Battery
Gunners -- 100 men
Volunteer Chasseurs of San Domingo -- 40 men
Cannons (18-lbr) -- 6
Cannons (12-lbr) -- 6
Mortar Battery
Bombardiers of the Navy -- 30 men
Volunteer Chasseurs of San Domingo -- 30 men
Mortars (6"-9") -- 9
[This OB came primarily from the "Pechot Diary" contained in B. F. Stevens' facsimile reproductions of documents of the American Revolution. French artillery figures are derived from Pierre Ozanne's map of the battle and the "Pechot Diary." Footnote from text.]
Hope this helps,
Jim