Gamer jargon. Someone who uses the most cheap and overpowered weapons/set up, items to win a game. It could be used in a general sense as well with someone who uses a cheap tactic or items to overpower the competition rather than using skill.

"full of cheese"를 구글링 해본 결과임. 게임용어라는데 대충 "날빌" 정도로 생각하면 될 듯. 최소한의 투자로 이기는 거(경기내용은 없고)