big challenge traffic sign on blue sky

big challenge major obstacle daunting task formidable difficulty substantial problem complex issue tough overwhelming barrier herculean effort grueling test uphill battle monumental undertaking massive setback pivotal journey critical impediment overpowering hardship weighty dilemma enormous adversity confrontation strenuous endeavor contest complication challenging quest grand ordeal overcoming conquering mountain battling difficult navigating uncharted territory rising occasion pushing boundaries testing limits breaking barriers defying expectations resolving surmounting challenges persevering finding solutions problems circumstances obstacles confronting mastering demanding triumphing