Surprised this was First place! 21 minutes, although almost half of it was saving up to 300b. Here is the design (bottom right was a jump pad deleted for box to be placed):
I got to 300b at 16 minutes, and when i was spamming upgrade on the investor I accidentally sold it, and lost all 300b💀.16/17 is def possible. Also I really love the idea of altered tiles, like the 4x. I can't wait for new levels later on.