Sorry, I don't know how to do replays. However;
You must minimise the number of conversion bombs you build. There are 10 areas of creeper at the start, you can build 5 bombs at a time. I used 9 in total with the 10th area eliminated by AC from the others. This is only possible if you stop the creeper escaping and spreading all over the map. So at the start build 5 bombs, dig and fill the map with shields to contain the creeper
Faster times are certainly possible