Some synonyms that could help you in creating a game idea: boost, increase, strengthen, add, amplify, intensify, raise, upgrade & magnify.
Some random inspiration for this theme could be: enhance your player during the game, enhance your opponents during the game, enhance the game world, enhance your team, enhance objects or structures, enhance relationships, enhance the HUD/UI and much more...
A game idea could be a platformer like Mega Man or a wizard in an open world who can improve his skills throughout the game.
So something needs to be enhanced or is enhanced in your game (Enhancements).
Hope it helps you and you can always discuss it with other participants in our Discord Channel (click here to join).
Be creative 😊 and Good luck and above all: have fun at this Game Jam!