So, a simple "run to the final boss and then die" is 12 minutes [0], but actual speedruns routed for completion have quickly dropped from 1.5 hours to under 1 hour just within the past week. [1] Speedrunners are very gutsy and innovative and are basically guaranteed to find ways to dramatically reduce times on a game this popular.

[0] https://www.youtube.com/watch?v=samulGnaDVg

[1] https://www.youtube.com/watch?v=IdYa2eAZ718