To start off, use all of youre first money on hiring people, then upgrade yourself. After you upgrade yourself, start upgrading the people you hired. After you and your workers are maxed out, get a Ak-47, its cheap and reliable. After, start upgrading you clip size until its at 50 or 60. Then, save up to get the Power Blaster. Its a one shot kill for almost everything. Thats how I beat the game.