Relaxing Challenge levels 20 to 29 don't work because
levels/easy/level20to29.json
SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data at line 1 column 2772 of the JSON data
I calculate those stats from your export, so they should be correct as of export format doesn't changes. I made this because I wanted know where to invest first.
At previous version (1.2.0) it was best to invest to Oil Company, after last update (1.3.0) Lemon Stands left cheap, but profit rises very fast, they get ~90% of my current profit.
For today mission, try use single mortar on map and one blaster per emitter and take 99% of map. Blasters can fire only from its final position near emitter, can not any more once it is there.