I guess you could do that using a cryptocurrency smart contract feature or a well decentralized betting platform to avoid the situation you described.
You will need to find people to bet with though.
It is a binary option trading, and for me it's the same as trading. If you bet that price will go over $10k it's the same as holding
Bitcoins and selling them when price do as you predicted. But in gambling if you make a wrong prediction you lose your bet, in
trading if price do not rise you still have your Bitcoins and you can wait longer to sell, but you have them.
I tried Binary option game and I didn't like it. That's not for me, I like traditional crypto-games more!
What makes betting on games gambling is if you take big risk. If you bet a dollar worth of bonus once, and you lose your bet, you don't consider it gambling. "Betting" should be the general term for them. The term "gambling" should be used when it involve big risk. This is why you advice people to bet little on good/safe games or bet what they can afford to lose, maybe until they are skilled and consistently profitable.
You can't call a person who has $10,000 in his/her bank account and use only $20 for lottery tickets per year, a gambler, would you? Lottery is a bet and win or lose everything "competition"