It's a bit late now, after 14000 views, but here's some instructions that will help you understand how the game works: (although it will probably become clear after the first fight)

Bring down the opponent's hive to win the fight. Block your opponent with your shield, and attack their hive when the moment is right. (aim at the hive and hold down the mouse button)
Your bees will lose health when they bash into the hive or the opponent's shield, give them time to heal from their wounds.
Blocking you opponent with your shield is a good tactic to send their bees crashing into the ground and restore your own health.

I've released a 'Bee Boxing' game earlier this year, based on the same concept. AI is improved in this new version. Also new are armed Queen bee Endbosses, rockets, and two strategic overview maps. It should also be more challenging, especially in the second overview map!