Search engines don't play our games - therefore, they don't know much about the game itself and cannot answer a question like is this specific mechanic unique. But take care to research your target market - people who pay point and click games might not want to solve an intricate puzzle to continue playing a point and click game.
If AI doesn't do a specific feature right - or can't do something you want - you're going to be stuck. You could spend a lot of time and money and end up with nothing. Whereas using game-development software gives you access to forums and experts that could help you out.
I've played a few AI created games that were fun. I've played more that stopped working after a few levels or were unplayable because the person didn't think of the little things that make a game playable - for example, you'd fall off the edge, it was too fast, or it became boring and repetitive very quickly. I think in these cases the developers were relying solely on AI, and AI let them down.
So, proceed with caution. Make the game if you're going to have fun creating the game. Don't make the game if you expect to make a good (or any) return on your investment - the odds are stacked against you.