Of course, I'm human... I'd want to treat myself too, but be wary.
I'd quit my job and work on Sindome fulltime.
I'd use 5 million (i would have to spend 5 million on whatever the eff I wanted) to set up a trust for Sindome, and the remaining 5 million to pay the staff a salary to work on the game full time.
Then I'll just put the rest of my money into retirement for my parents, me, my boyfriend, and my girlfriend.
If I still have money left then I'd offer my girlfriend a "small loan" to start her dream game dev studio.