"Unrealistic demands" refers to requests or expectations that are unreasonable or impossible to fulfill within a given situation or context. Full definition
A compromise that would allow the government to fulfil its manifesto commitment without placing unrealistic demands on the trade union movement. (theguardian.com)
When dealing with huge expenses like a car repair, the last thing you want is a lender who's making unrealistic demands when the time comes to pay back the loan. (nation21loans.com)
Simply because it makes wholly unrealistic demands of the player for most of the game. (mechadamashii.com)