Your project sounds wonderful! For legal considerations, ensure you avoid using any trademarks from "30 Seconds" or 999 Games, like the name or logos. The rules of the game can't be copyrighted, but the specific text, images, and graphics can be, so your different design and content should help. Patents on board games are rare, but you should check if "30 Seconds" has any and make sure you don't infringe. To stay safe, introduce enough variations in the game mechanics and consider consulting a legal expert in intellectual property to guide you through the specifics. Best of luck with your game!