Only one person, in five days?! Amazing work!
This has the most promise of the games I've played in this jam so far, I *love* the dynamics between wanting to reach new areas, as well as making yourself enough space to run around, and with more beasties spawning the more places you reach- it's all right fun!
If this were a larger project I would adore seeing more juice in the upgrade system- unlockable land shapes and types maybe, some interesting weapon bits- maybe a cooldown on the land placing, even if just a small one, that you could upgrade to speed up?
Either way, lovely, lovely work, this one's super interesting. <3