As @redonihunter already told you, Itch doesn't block content in any way. If a game isn't working for you, it's for technical reasons. If all games using a certain engine aren't working, it's because your computer is too old or too limited, and the only solution is to upgrade.
I understand it's not the best answer, but it's not possible to perform miracles if your computer doesn't meet the minimum requirements for a game.