There is a game development site called Flowlab (https://flowlab.io/games) that has a lot of games that I think could be really good for speedrunning. None of them are listed on Speedrun.com yet, so I was wondering what gives me the best odds of getting a game accepted. I'm really passionate about speedrunning these games and it'd be great to have some other people who can compete with me! Thank you in advance!

These are the types of games I'm speedrunning https://www.youtube.com/@CodeAlpaca/videos

Create a support ticket: https://www.speedrun.com/support/tickets/new choose "Add new game", read all the associated rules.

At a brief glance, I suspect many of these games will not meet the site's criteria for new games, but definitely read them over yourself, and if you think there eligible (or you're just not sure) then go ahead and submit them.