True Last Boss

Many shooting games include a "True Last Boss (TLB)," a hidden boss encounter that only appears to highly skilled players. Reaching the TLB of a game often requires meeting a series of requirements, such as achieving a "no miss-no bomb (NMNB)" run, reaching a certain score threshold, destroying certain objects, entering a certain "path", or other objectives that can range from the obvious to the esoteric.

Even just reaching the TLB is a high achievement, and defeating them is, in some cases, a much greater challenge than an ordinary clear of the game.

Games that feature a TLB
For a list of games that include a True Last Boss, see the category link below with the same name.