At the end of the stepping stones game, the remaining panels are shown being shattered into sharp fragments that injure the surviving players, in one case grievously. But how can this be true if (1) many of the regular glass panels were already destroyed in the course of the game and (2) in particular, the remaining panels closest to the players were all or nearly all tempered glass? The entire purpose of tempered glass is to avoid creating such dangerous fragments.
The VIPs are wearing golden animal masks. Some of them take glasses of wine. But there's no way they could drink the wine from the glasses while wearing the masks they have on.
When the file of player #17 is shown, his birth date reads 1897.03, when it should be 1987.03 as he's a fairly young man. This has since been fixed by Netflix.