I'd love to help, but to be honest I'm a little confused. Let me ask some questions to understand the situation better.
The Peasant 540 A-Go-Go is a peasant cube I curate for my friends to play whenever we get the opportunity. We went with unpowered because we want the cube to lean toward interaction
By "unpowered" do you mean without rares? In peasant cubes it's common to see a ton of roleplayers but fewer cards that are interesting by themselves. Adding rares would probably help with the feeling of incompleteness, which I get as well when looking at peasant cubes.
Interaction is not dependent on rarity restrictions. It's true that formats with very fast mana can have T1 combos and unbeatable draws, but it's still highly interactive on average if there is enough counterspells and cheap removal available.
So a few important questions:
1. Would you like the cube to be peasant?
2. How tolerant is your group to variance between games?
but we also didn't want it to be entirely bereft of win conditions.
Creatures are win conditions in limited, so it's really hard not to have win conditions. Maybe you're missing big, splashy plays?
3. Do you want the environment to be faster (small creatures win the game most of the time, tempo centric) or slower (large creatures or combos win the game most of the time, card advantage centric)?
4. Do you want to include combos as wincons?
5. Do you want to run large finishers as wincons?
It plays infinite combos and archetypes players seem to shy away from like land disruption and mill.
Land disruption doesn't seem very well-supported, but it might not even be a good idea. Most players hate losing to it, and most of the time it's not even an optimal strategy. Mill can be uninteractive and feels bad to many players are well, but being careful it can also be an exciting deck to play. You didn't pick easy archetypes
6. How much do you want the cube to be about synergy and how much do you want it to be about generically good cards?
7. Why did you choose these archetypes in particular? Do you like to play them? It's easy to make the mistake as a designer to seed in the deck you like to play the most, but it's the deck that people hate to play against. OTOH, "hate" can be overstated and there is a debate of whether strong feelings against it can be a good thing for the cube:
https://riptidelab.com/forum/threads/emotional-spikes-in-cube-design.1439/
I get a bit into that in my article about player agency:
https://cubecobra.com/content/article/6090e6e2a92ae8104cffc78f (part 1),
https://cubecobra.com/content/article/609dcaf8028ce9104b067ac3 (part 2)
It feels... incomplete, somehow. Less intuitive and functional than I want it to be.
8. I can't make sense of those three adjectives, especially in conjuction. Can you explain the feelings better?
I'll take a stab at it, but I may have misinterpreted:
Incomplete may mean it's missing some part of Magic you enjoy. It would be good to isolate it.
Unintuitive may mean it's missing direction - wincons or archetypes maybe? Things you know you can win with (because they match the feeling of "winning a game" that you're used to and experienced in other formats).
Not functional may mean the execution does not match with your vision. Next step is probably to go back to the vision and iterate on it, define design goals, then make concrete card changes that work towards those goals.
I wanted to get some eyes on it and see if I'm just overthinking it.
Playtesting is the best way to figure this out. You get more insight from a bit of playtesting than from a lot of staring at CubeCobra. If you'd like, I can 2p draft it with you and play afterwards, but nothing beats playing with the audience you're building the cube for.
