Hello,I think that i can do it in 3-4 days.
I have worked on unity 2d games for about 5 years, and i have made some good games, if you want some screenshot i'll send them to you.
I'll use unity 5 to do the job, please contact me on my email, if you want from me to do the job, and if the price is high, i'll make it 100$ because i'm new in freelancer.
Thank you.