A lot of game designers have a lot of good ideas… and some of them even work. Skyrim, for example, implemented a lot of great ideas that just hadn’t quite jelled in previous entries in “The Elder Scrolls” series.
Then there’s other games, where great new ideas just turn out to be awful. Here’s some good examples.
About the only thing I can suggest, on this topic is: PLAYTEST. Whether for tabletop RPGs or videogames, playtesting is where its at, so far as finding the weaknesses inherent in your designs. Theory is all well and good, but nothing replaces actual players actually playing the game.