Hi Partner,
I believe it can be expected that with a huge initial investment having been put into a start up company, they may want to reach breakeven point as fast as possible. This could result in long hours of work, wide variations in salaries among reportees and team leaders, less leaves, cost cutting measures on administrative facilities etc.
So, for a start you could try working on policies related to leave & attendance, compensation, statutory benefits such as PF and ESI, code of conduct, performance management.
As candidates may want to know more about compensation and benefits before joining, you could place these on priority for quick formulation.
Hope this helps for a start.