I have a question about the Onslaught game for WiiWare.?

I was considering buying Onslaught on WiiWare. I was just wondering, is it multiplayer on the wii? I know that it has wifi, but I wanted to know if it was multiplayer without getting online. I do not llike to play online that much. I want to know if it is multiplayer without the wifi connection. Please answer me. Thank you.