Cannon Fodder but harder+painjob
first off you should read the "Untold Story" from the level designer himself, Stuart Campbell.
"worldofstuart dot excellentcontent dot com/cf2/cf2.htm"
there was suppose to be a proper manual/ novella to go with this game but it didn't make the cut, so the designer made some webpages to explain it all, along with some hints. at least read it for the plot/backstory. also a great source of nostalgia for britpop history, which influenced the game design.
with that out of the way, i must also say the default DOSBox settings are probably wrong. it auto runs at MAX cycles which can lag the game. the game is best run at 20000 cycles or maybe 60 percent depending on your CPU. "output=ddraw" (DirectDraw) worked best for me, but Overlay might be more compatible with most GPUs.
gameplay? more of the same but harder. colour scheme in some missions might be horrible because funky aliens. IMO too many missions force you to run straight to the rocket shooting enemies to take them out ASAP. some missions are too puzzle-like for my taste, and don't give you much time to thinking about because enemies start shooting rockets or hurling grenades at you. first game was revolutionary for its time, but we eventually got more complex RTS games(like Syndicate and Dune 2), and this sequel feels quite dated. still mostly enjoyable but i prefer the first game, which i still never beat.