I tested it out and it did for some reason download as a zip file, I think it's an issue with Mediafire, so I switched it to Dropbox.It automatically downloaded a .jar.zip file, still only have to put it straight in the mods folder though
it's been 2 months. any updates?ExtendedPlanets v0.4.2 has been released after only a year of inactivity! Also, if everything continues going smoothly, the 1.12.2 port should be out soon. I wish I could give an exact date, but as can be seen I'm pretty bad at that.