just tell me please

There is no co-op mode. You can use the Shovel Knight amiibo to summon another Shovel Knight to help you out in levels but no-one can control that Shovel Knight. Why did you think there was co-op?

There is a co-op mode. But you need the SK amiibo for it. One player controls the normal Shovel Knight, the other controls the amiibo version. The amiibo player is able to use completely new items and can custom his SK. The amiibo also unlocks new challenges and will be used in future games by Yacht Club Games.

... i mean the battle mode

The developers once stated that there'll be a battle mode in a later update.

ok anyways i haz the amiibo