I read the guidelines (Moral and National Education Curriculum Guide, 德育及國民教育科課程指引) published by the Education Bureau. It is not as bad as the teaching manual (中國模式國情專題教學手冊) written by the Baptist University, published by a pro-communist organization with funding from the Education Bureau. It does state that it encourages students to consider issues from multiple angles, independently, and rationally, sort our conflicts in values, and to make judgments rationally.
However, it presents a predominantly positive view of the country. It writes extensively of the culture, the achievements, the leaders, developments, the economy, ... It says nothing about critical issues such as the dictatorship of the Communist Party, how common people can (or cannot) participate in the political arena, the conflict between the mainland and Taiwan, pervasive corruption, degradation of the environment, the suffering in the rural areas, ... It does, however, emphasize the contributions made by the leaders of the country - by that it probably meant the mainland, not Taiwan. It talks about natural disasters but not man-made disasters. It mentions, in passing, problems faced by the leaders of the country, and those faced by Hong Kong and the country. That is as critical as it gets.
The message is to love your country, and do not ask hard questions. That is a problem. If the mainland is in such good shape, we won’t need the 50-year no-change guarantee for Hong Kong. Why aren’t we allowed to face the reality openly and honestly?