NFL Blitz is a port of the successful NFL Blitz arcade machines from Midway.
The game features an extremely simplified interface, and gameplay to match. Rather an a simulation, Blitz is an extremely exaggerated version of football, with humongous players that can run extremely fast and deliver hits that send players flying tens of yards. Since all of the players have nearly superhuman abilities, the downs are done on a 30-yard basis instead of 10 yards. Plays are very limited with the simplified interface, and all kicks in the game are done automatically.
The traditional rules of football do not exist in Blitz, so as to not slow down play. Pass interference, roughing the passer, and late hits are completely normal. Players also celebrated quite loudly after making hard hits or scoring. These aspects would be limited later on in the blitz series as the NFL became more strict with its license.
You can keep track of your stats in NFL Blitz using a name and code, much like a fighting game. Certain names let you unlock special characters, such as Raiden.