Last I thought, a donation was an appreciation in the form of currency. Not some type of necessary payment... This seems to make it sound that way. If it were my choice I'd just let them keep fixing bugs and adding features whenever they want. If all Construct development were to stop right now and you had just donated a bunch of money to it, would you be mad? I wouldn't. I'd feel bad cause I really enjoyed the program but I'd be happy cause I donated to the developers of a great project.