After a minute the boss spawns and speeds up the enemies. This game looks cursed when you press space it starts his punch attack and K for his kick attack.
Use space to punch the evil forest animals and K to kick watch out for the flying cat he is really fast. After a while a frog comes out of the sky and helps you and every so often you can throw potions. Use right arrow to move through the intro slides. Use S to skip intro. Actually kind of difficult because sometimes the rabbit and the flying cat spawn at once and you can’t kill them both.