I am currently trying to speedrun the N64 version of the game, and I want to know what is considered In-Game Time so I can more accurately label any run that I may submit.

Sorry for the slow response. I can see why IGT might be confusing considering the strategy in the IL records. Right now the ruling is "Time elapsed per the in game timer (the red countdown at the top of the screen) when you retry, end run, or soft reset out of the level. For full game runs, the sum of these times is IGT.”

IGT is not really important or even required in full game category submissions, only the RTA. It’s a nice benchmark to see, but because of the way the timer works, we only measure ILs in IGT currently. In ILs, you are allowed to End Run (thereby stopping the timer on an N64 console), and continue your combo afterward.

Thanks for letting me know.