Slowly working through the last level. Was a fairly enjoyable campaign, although sneak attacks that caught me by surprise have led to more than one reversion on this final mission (Those Allied naval cruisers, escorted by a couple of destroyers, are the pain that I thought they could be when I briefly tried them out during the Allied campaign, except I'm at the receiving end of their guns.).
Edit: And one thing I really hate that we haven't talked about, is how the naval units in this game can appear from off-screen. Not enough to destroy their naval bases, since units can still appear if they're scripted to routinely make an attack run. There's a tiny bit of this in the original C&C, where I remember several enemy units in one mission that appear from no where, off-screen, but the Allied naval ships do it frequently in Red Alert.
Not sure I have it in me to play through all the extra missions (Which to the best of my knowledge, are all designed to be even more difficult than the base game, which just sounds like a turn-off to me, as you no doubt can sympathize with). And I definitely won't be going back and replaying these two campaigns anytime soon to try the alternate paths. The exact opposite of what I did with the original Command & Conquer. Didn't want to finish with that one, but I literally just ran out of stuff to do.
Super Mario 3D World has called and I played through world 1 today, so I think the classic PC gaming is going to end for a while after I finish this last level.