Game feeling is good overall, the way you managed the audio especially makes it stand out. It's fun to walk around the planet, and I could easily see the game being expanded with more maps, types of seeds, enemies, etc etc.
Only real gripe I have is sometimes when you're going down it's really hard to see the ships chasing after you because of the camera, and I've had situations were they would spawn right in front of me, although I guess it's on me to plan for that scenario and make sure I always have one energy left :p
As for additional polish, not sure what the grid highlight was for, as the seed is planted right below you. A timer that tells you the duration of waves would be great. Having the esc key pause the game instead of sending you back would be a small and good QoL too. Finally, a gauge above the battery seed to let you know when the next energy point is awarded could also help planning accordingly.
I feel like I've talked a lot about negatives or what could be improved but that's only because I've found it fairly enjoyable with plenty of potential and it got me thinking about everything I'd like to see in it! Well done :D