As long as there's a risk involved and it is some kind of prediction, win or lose type of games, then I would always consider it as a form of gambling.
Sometimes even if it's not directly money as long as it have a value and it is being risk then yes it is gambling.
When it does not involves money, how can we say that it is risky or contains some atom of risks. When we gamble it always involves the risk of losing money unless it is a free spin or bonus for us to try our luck. Gambling could involves money, bet, material things or something that will cost us something. I know I have placed many free games in form of bonus and if I win I do take the money that is involved which is what makes it gambling because of the finance that is involved which is the reason many gamblers would always want to gamble.