So making an RTS for a jam is really ambitious like everyone said, and its amazing that you got this much done! And the inspiration from warcraft+starcraft games, and that terran marine death sound brings a lot of good nostalgia.. :)) That being said, you order a portion of nitpicking from the chef, so here it comes!
***Small(jam versions) nitpicks:***
-Unless the install version has something unique compared to the zip one, id say its better to just remove it since its a bit confusing!
-Add so that the Escape gets you back to the main menu instead of quitting the game. Since once the player starts the mission he has to finish it or reload the game.
-The F1,F2,..,F12 keys these days are commands for laptops so they are unusable in a way.
-The 2nd mission where you need to gather 5000 resources shouldnt have red crystals in it, since getting your hands on one also means that you finished the mission in a way. So just having only trees and a few blue minerals here and there feels more balanced.
***Big(post-jam versions):***
-The collision boxes for units should be a bit smaller. Without a fully polished movement system this will help a lot with moving around the map..
-Look into the A* search algorithm, it takes a bit of time to understand it but once you do its a really good way of making AI movement in most games! I know there was a really good tutorial on "The Cherno" YT channel but it was in Java so i dont know if that helps. Also its good because i see that you made a map using a grid system which means you already have a great base for it!
-The A* system is also great for AI that fights back!
***Extra:*** I saw you did a lot of similar games like this during the jams. So my advice is to try and reduce the scope of your projects, or joining a longer jam so that you have enough time to really make the game you wanted! :)) These are all great basis, but making a full RTS is impossible in the short span that is given for LD. So maybe make some hybrids by cutting out certain parts out, like Legion TD, Tooth and tail, They are billions etc... Good luck i hope i get to see another strategy game from you in the jam to come!