First time I played I won in about 2 months, it is an awesome game. My tips are 1. The HR people are kinda redundant, if you have the fully upgraded gym, bathroom, cafeteria they give full happiness to workers. 2. The researchers should be upgraded ASAP and try to cluster types of workers in the same office, specialized office upgrades really help.
22 days, but I think I could've done it faster. I thought I needed a ton of money, which was a lie. By the time I finished, I had $12mil. I made a ridiculous amount of Accountants, upgraded most of my workers, and had lots of supervisors.
If I played again for speed, I'd be sure to make more researchers ahead of time, since it took me 3 days for the last goal.