There is 3 hay in the wheat field they are a bit hidden after eating them and other hay's on the ground you are able to buy all upgrades, after buying all of the jump upgrades you can jump on the roof of startig area and finish the game by eating last hay's up there.
As other challanages unfortunately there is't any in the game right now but if I had time I would make a second level where you save your egg and. It would be good place to add new challanage. Maybe I can add it later.
Thanks for playing hope you had fun.