To skip the mario head sequence when you start the game, change

exit_and_execute /*seg*/ 0x14, /*script*/ _introSegmentRomStart, /*scriptEnd*/ _introSegmentRomEnd, /*entry*/ level_intro_entry_2

to

exit_and_execute /*seg*/ 0x14, /*script*/ _introSegmentRomStart, /*scriptEnd*/ _introSegmentRomEnd, /*entry*/ L1

in levels/intro/script.s at line 20.

This tutorial was originally posted by “Revo” in the N64 Decompilation discord.