This is quite a loophole you've found here. Do you know if would be legal to allow users to opt-in to playing randomly? It could still technically be a game of skill, and players would just be choosing not to use skill. Then, it literally would be a lottery.

I really think you need to heed the lessons of fantasy sports for money. As long as you are flying under the radar, you may be fine. However, as a VC, I wouldn't even consider investing in this, because I would worry that if you ever became wildly successful, then regulators would step in (changing the rules if they have to) and shut you down.