This might sound a bit random, but Cyberpunk 2077 has this sort of warmup sound that plays through the game startup sequence that always gets me relaxed or psyched up to play. Another example is the title song in Trails from Zero. Calms me every time.
Whether it's a sound effect, music, or a loading screen, is there a game that does this for you immediately when you open it?
That combined with the Final Fantasy Tactics opening music is 100% nostalgia fuel for me. Always that twinge of anxiety later on too when you weren't sure if you'd get the second part of the jingle to let you know the disc is working.