I don't think we define whether a work is a game based on its difficulty. There is an aesthetic, an exchange between the player and the game, possible interactions... I'm not going to make the complete list but this work respects many criteria that make it a game. Whether it brings you a challenge that is up to you or not is one thing, but the work of others should not be denigrated just because it does not meet our expectations.
Far from judging you. Like you I only give my opinion.
Sorry if I offend you with my intervention. Have a good day.