I almost made it to Final Frontier, I think with a few more tries I could beat it! I am a fan of the roguelike-with-progression because I don't feel bad when I die so often, at least I'm making *some* progress. I like how you unlock the worlds by gathering resources from previous ones. Even with a limited set of mechanics and art, you were able to make a very playable game that lasted a good 15-20 minutes for a full playthrough--great job!
The map was nice, it would have been neat to see already-visited cells marked somehow although I still had no issues finding my way around. I liked the paths marking where to go so I wasn't lost. I think it would have been interesting to see walls or some other puzzle design within each cell to make things harder--it wasn't until the second to last world that I found it more difficult, but that's probably perfectly fine for a LD game.
As far as the theming goes, it would have been interesting to understand more about why I was in this world trying to collect things, communicated through art or level design or something. I think the "fun" is there but maybe trying to explain why the player is doing what they're doing. Even though I have a sword, I shoot bullets and I can also collect rocks and wood--it works but also feels a bit strange. Maybe having melee combat would fit better and some downside to using it--right now I can shoot without any repercussions. I remember listening to a GDC talk by the guys who did Nuclear Throne and they said, "If the player has no reason not to shoot, they should always be shooting," which felt true here. Either there should be a consequence to shooting or I should always shoot.
Overall this was a solid entry. I think finding what about the world or mechanics make it unique will make it more interesting to people, e.g. I really liked buying things to help me progress, but what else could be unique to your game?
Great job, I had fun playing and look forward to seeing this in action someday.