Generally if it's under 5 minutes it's considered too short
@Tymeggs A thing to bear in mind is that the rule applies to the length of normal/casual play. If you found some monster skips that cut out 90% of the game and turn a 20 minute game into a 2 minute speedrun, you should use the additional notes field to explain that thoroughly.
If a game has a monster skip that cuts almost the entire game, that's nice and all for potential any% categories; but this shouldn't be used for game requests. As the request rules say - you should showcase the majority of the game in your run, otherwise it might seem short and trivial to the site moderators. You can't judge a game if you don't get to watch it first.
Generally speaking just go for maybe a more casual run to show to the moderators so that whoever is verifying the game can see that the game ITSELF isn't something like 10 minutes.
Or just submit a no skips speedrun since that shows more of the game.
You could request the game and tell the mods that there could be other categories - the main category could be under 5 minutes, but there could be other harder categories/challenges that could be closer to 20/30 minutes. Some of these could be 100%, low% (I dont know what the game is)