WRECK IT RALPH SOUNDTRACK FIX IT FELIX MOVIE
The only reference to him in the movie mentions him passing down the hammer to his son. Doylist reasons aside, which peg it as a reference to Donkey Kong Junior, the name means that there's a Fix-It Felix SENIOR. The game is called Fix-It Felix JUNIOR.So its probably a routine that only happens whenever Felix "dies" if the game is not being played. Most attract modes give the "player" one life. The game is probably supposed to be in Attract Mode, given since that particular death animation only appears when the player gets a Game Over (as seen in many of the Defictionalizations of Fix-It Felix Jr.).They might not have known he would recover the same way.
Given that Ralph was excluded from their social circle before the events of the movie, they'd probably never seen Felix "die" outside a game-in-progress before.Therefore, the evidence suggests that Felix regenerates immediately in either case, only the regeneration after Game Over is never seen by the player. If Felix has a life to spare when he dies, he simply drops off the bottom of the screen while flailing his limbs worriedly. This is probably incorrect: Assuming it's true to the real-life game of Fix-It Felix Jr., Felix only uses that death animation if he doesn't have an extra life.In which case, he would have stayed "dead" until someone put a quarter in the game tomorrow, and that would have ruined their party. They might not have known that he had an extra life.It's like us humans getting goosebumps when we're feeling cold - we know that they're useless because we lack long fur to protect us, but the reaction is hardwired into our body and there's little we can do about it. To borrow an analogy/explanation from Kid Radd that might fit here: The Nicelanders are programmed to see Felix dying by Ralph's action as a threat to their home, and have a corresponding knee-jerk reaction.