Amazing.
Words cannot describe how fun that was. Instead of describing it, I'll make a walkthrough since you haven't yet.
Quick notes:
Use patsies, on every mission, the best ones are the increase success rate ones, the Tudor is my favorite.
When starting out, STEAL MONEY LIKE CRAZY, it is very useful when you don't have businesses to support your operation.
Always have a henchmen wandering, I only used two henchmen, I originally bought femme fatality, and then after she died (i made her fight alone because I wanted a new henchmen) I purchased I.V. and she stayed the rest of the game.
Walkthrough of success:
First, get around 10 minions, then steal a science. Next, steal money and alternate between the two, until level 2. Level 2 means business. Start your legit financial empire, which will become increasingly important and useful. Buy all 6 turrets, i recommend repeating turrets, then continue stealing science, and when you can, start robbing banks and stuff, there are only two real necessary missions to complete the game. Purchase Railguns if they are available, if not, unlock them.
Once you have some cash, you can start to upgrade, your first big step is to move to the moon, unlock it and get the 30k to move, its the best decision you can make. Build 6 turrets, REPEATING ONLY. Now fill up your control rooms and your financial room using 30 minions. Buy the other 20 minions for defenses and missions. Rob places until you are able to buy out all available businesses, and then steal science to unlock the rest of the businesses. Once you have all businesses unlocked and purchased, go you can focus all out on science.
Just run missions, once you have the A.I. control rooms, you will have your 30 minions back so put them on permanent patrol. On attacks keep your pool full and deploy as necessary. Continue to finish your sciences and then blow up the Earth.
Took me around 2 hours, I hope my walkthrough helps.