Hi Gapetit,
I played the Second Front scenario many years ago and along with Red Front is certainly one my favorites, though a little controversial in its design.
As I remember there are 5 factions in the game, 3 German (Kriegsmarine, Luftwaffe and Army )and 2 Allied (Ground Forces and AirForce). You have can only play in HotSeat mode and only control the Allied ground forces as the Allied Air Force is an independent faction. I'm not certain why the designers did this, as I feel they could easily have incorporated the 3 German and 2 Allied factions into just one faction for each side.
The other issue you need to be aware of is that the scenario is designed to swap game files (game.txt, rules.txt and event.txt ), I believe a dozen or so times in the game. It uses a bat file to do so but in today's terms you would need to ensure that you coded the bat file to be able to work for 64 bit computers as well.
Even more significantly it used the delevent.exe file to erase the previous events. Again this is potentially an issue for players with 64 bit computers as the older delevent event file won't work on their computers. They need the updated delevent.exe for 64 bit computers and even then the bat file won't properly erase the previous file.
I recently replayed Red Front and had to 1) comment out the delevent command from the bat file (i.e. : DELEVENT RF.sav) and 2) whenever the game asked me to swap files, manually drag and drop the newly saved sav. file over the delevent.exe to ensure that the previous events where wiped clean.
As such, not all players might be willing to follow these steps, but for others the relatively small inconvenience is well worth the effort. I had a blast playing Red Front again and would certainly enjoy replaying the Second Front as well.
The only other issue, I might recall having was that the ground tiles didn't have the stackable feature thus one of your stacks could easily be killed by a single enemy unit. TNO stack kills function would have been a great addition though I don't know if it could be added today without affecting play balance.
EDIT: You control both Allied factions but they don't play at the same time. I think first you play the Ground faction and once you completed your turn you get to play the Allied Air Force (or vice-versa).