Shmacky-McNuts: There is a logical reason for the beginning of a game being best.
1) The developer has more excitement and begins with all their effort, compared to the deminishing return slog of actual work. As in, the sparkle and magic slowly leaves the creator when fun turns into a never ending work load.
2) Play testers rarely ever reach the end of a game. Thus the "we need X...." only happens in the beginning of a game and thus the end seems empty. Since nobody but the dev team payed a visit. Which also credits any good end to the dev members or truly good testers.
3) End?? As long as the marketing dupes you into thinking the dumpster fire is "good enough" at the start, they have your money before you figure out you were robbed.
As a caveat; one may enjoy an entire game about the beginning if it has enough parts and randomisation to it. A good example would be Cataclysm dark days ahead(in spite of their devs and broken game).
RimWorld and Unreal World are a few other examples.
Life itself is the most engaging game of this as an example!
edit: yet more typos, I type to fast >_<
On the other hand, there is a tendency of game developers to create the first level first, which is not a good idea because the level designer is less familiar with how the game plays, and that can result in the first level being dull or not being of an appropriate difficulty. In fact, it's common advice among game developers to not make the first level you make the first one in the game.