Excellent work, 80% is still an 'A' grade.
Darn right! (Although 80% is a B, but it should be an A :b)And let us remember that this is PC Gamer here; the same people that absolutely do not hesitate giving 50% or less to immensely expensive AAA titles that took 2 years and DirectX 9 to develop.
John: For single player stuff, perhaps you could check out a sort of puzzle-style design like that mode in Worms?
That way it isn't quite as important to write complicated AI but the game would still be still fun.
That could also make single-player quite different from multiplayer so the two modes don't cancel each-other out and so they both are fun in their own ways.
Anyway, something to ponder if you haven't already...
Again: well done!