Finally got the sub 20 hours! Massive improvement here, really happy with this.
Completing this game is defined as getting the final credits, after beating the Rival in Round 2. To do this, you must complete all Stadium cups, and the Gym Leader Castle in both Round 1, and Round 2.
In speedrunning this game, only the rental Pokemon are allowed (as using imports would be far too easy, and too boring). This makes some of the fights really tricky and interesting to work out, as the opposing Pokemon are much better than you.
Twitch stream: https://www.twitch.tv/werster
Discord server: https://discord.gg/0jCpl8wIKvQWXJaP
Speedrun profile: http://www.speedrun.com/user/werster