What are some alternatives?
When comparing Tuxemon and Pokémon (series), you can also consider the following products
PokeMMO - PokeMMO is an Amazing, Action-Adventure, Massively Multiplayer Online, Role-playing and Puzzle video game that provides with the same mechanics and gameplay as Pokemon.
OpMon - An open source Pokemon clone, with monster fights
EvoCreo - Embark on a journey through the world of Zenith.
Temtem - Temtem is a Massively Multiplayer Online and Role-playing video game released by Humble Bundle for PC and expecting to release for Console in earlier 2021.
Pokemon Showdown - Pokemon Showdown is a 2D, Fighting, Single and Multiplayer video game.
Pokemon World Online - Pokemon World Online - Free Pokemon MMORPG.