We propose an interference-aware MAC protocol using a simple transmission strategy motivated by a game- theoretic approach. We formulate a channel access game, which considers nodes concurrently transmitting in nearby clusters, incorporating a realistic wireless communication model - the SINR model. Under inter-cluster interference, we derive a decentralized transmission strategy, which achieves a Bayesian Nash Equilibrium (BNE). The proposed MAC protocol balances network throughput and battery consumption at each transmission. We compare our BNE-based decentralized strategy with a centralized globally optimal strategy in terms of efficiency and balance. We further show that the transmission threshold should be adaptively tuned depending on the number of active users in the network, crosstalk, ambient noise, transmission cost, and radio-dependent receiver sensitivity. We also present a simple dynamic procedure for nodes to efficiently find a Nash Equilibrium (NE) without requiring each node to know the total number of active nodes or the channel gain distribution, and prove that this procedure is guaranteed to converge.