The start to this one is pretty rough. The title is "Serious" though. So I made it serious. And dangerous.
I completed all objectives in a little over 6 minutes, which is about a minute faster than my best time for the original CW4 map. The original map didn't have massive amounts of creeper to have to deal with.
A couple of tips follow for those who get stuck:
Spoiler
It is rather critical to Instant build and ERN your Miners. Next, ERN a bunch of cannons. And then ERN mortars. In short, apply an ERN to basically everything.
Spoiler
Removing the walls with the Leveler was rather helpful as well. Cannons shoot better at stuff they can see.