I like this game, it's so easy that it's boring... like watching a crops growing up. Jokes aside, I think this game has a potential and it can be expanded with more crops, a purpose to earn/spend money etc. It is easy and it fits "No Enemies" theme well.
However, there are two things I don't like in this game. Controls are not comfortable as they could be. Well, player enters UFO with E key, but in order to get out of UFO you have to press Escape. That's unintuitive. The same goes for cutting down trees/wheat crops(Shift and LMB I think?) and planting tree/wheat (Spacebar vs LMB). That feels very strange. When you are inside while circle, it should be obvious you are intended to plant wheat seed, not tree sapling. I think if you could unify those 3 pairs, the controls would be much better.
Second thing I don't like is: Until you find shop, there is no reason to do anything. Look at player's UFO. It has potential! Instead of searching shop in the middle of nowhere, player's vehicle may have a very advanced technology that transforms wood into wheat, rye and other crops you wish to include in the future. If I were you, I would get rid of shop and implement exchange system inside that UFO.
Few improvements and this game will be much better. I like the fact you created farming based game for this jam as I don't see a lot of games including this mechanic. This project is definitely worth improving and further developing. Good work!