You can make your own custom levels in Hot Lava and even help out with community translations! https://steamcommunity.com/app/382560/workshop/
If you want to help with your own translation check out this post here: https://forums.kleientertainment.com/forums/topic/95685-creatingusing-language-translations/
You can find more details about creating your own maps here: here: https://cdn.forums.klei.com/HL/modkit_readme.pdf