Lottery won't work for sure, unless you put millions of US Dollars in advertising. Without a proper advertising people would only take part in a lottery if it's absolutely free. People won't pay $0.02 to participate in an unknown lottery, let alone $2.

And, I'm sorry I don't want to be a d*ck here, but IMO "a new Space game" would look lame compared to existing ones. Not because you don't know how to make it, but because you don't have millions of USD to make the game look good.

If you are really good in creating games with HASH SUM verification you can find a well-paid job, but I wouldn't advise to compete with established gambling sites.