GunBound is now being revived at mobile devices by New GunBound. Sporting the same gameplay mechanics as the original, New GunBound is having a closed beta test starting tomorrow, January 15, 2020 until January 22, 2020.
You need to pre-register via this website in order to participate in the closed beta testing. The testing phase will officially start on January 15, 2020 at 5:00pm (UTC+8) until January 22, 2019.
If you’re still on the fence about New GunBound here’s an official list of units that will come with the game. It is safe to assume that the developer will add or remove characters as the game’s development continues.