Various types of exotic promising engines are considered, including very controversial from the point of view of physics. This is the acceleration of the spacecraft using an external source of matter and energy, engines with leakage into an artificial atmosphere, using a space magnetic field, with a closed cycle of the working fluid and similar designs, thermonuclear, using high-energy particles, using the structure of space and a number of others. A fairly detailed overview of the proposals for these engines is given, including the author's own proposals, as well as their analysis and assessment of possible characteristics. For those interested in the development prospects of various types of space engines.