Hi there. Here is a small selection of ideas I've had while playing and that I felt could be implemented.
• More building blocks :
As others have asked, it would be nice to be able to create more shapes of walls and foundations. It would also be nice to have floor blocks that are as thin as the walkways to make the upper levels of our factories.
Guardrails that could snap to foundations would also be quite a nice addition. Right now, I feel somewhat forced to add walkways around all my foundations to make guardrails.
Also, some walls with electrical connections on them. I keep making doors to have my electrical wires passing through them, and it feels wrong.
• Accessibility category :
We already have jump-pads, and as fun as they are, they seem somewhat unreliable since you don't know until you've used them where you will land. Plus, the curve you will go in the air depends on how you stepped on the pad, and if you haven't put U-Jelly pad at the end, you will most likely take damage.
Instead, I'd rather have a good ol' ladder which I could snap to a wall or foundation, or to another ladder block to extend it. That would make access to upper levels of my factory waaaaay easier.
Also, what if we had elevators that would follow a rail which could be snapped to a wall or foundations? That could be a top-tier thing.
All of this could be placed into an "Accessibility" category in the construction menu, and you could move the Jump-pads there too.
• Upgrading more builds :
I've discovered super late that I could upgrade a conveyor belt to a faster model without having to remove the old one and replace it with the new one.
I feel like this could apply to way more things. If there's space to upgrade a storage unit into a storage unit MK2, I think we should be able to do it without having to empty the old one, removing it and putting the new one in its place.
Same with Splitters and Smart splitters. Since they look so similar, I'm surprised that I can't replace all my splitters by smart splitters to stream-line my factory a lot more.
Again, same with the power-poles.
• Conveyor frames, poles and beams :
A great tool that we could certainly use would be something like those perpendicular conveyor wall frames, but... not on a wall.
I'm suggesting something like the ability to build poles and beams, and the be able to snap conveyor frames like the ones we have on walls. That way, we wouldn't be forced to have our conveyor belt anchored to the floor or to walls.
• Genetical engineering :
I don't know, I feel like something missing from my factory would be a way to put a power slug directly into a vat and have it power things-up.
And also I think it would be super nice to be able to put consomable fruits like paleberries and nuts into a vat and have them slowly reproduce, to have a somewhat regular source of life points, especially after you died. And maybe you could plug these food-vats to a machine that heals you when you step on it?
• New Game + :
This is something for the future, I guess, but I'd like to be able, once all tiers are unlocked, to start a "New Game +" on a fresh map, but with all the researches I've unlocked in a previous game from the get-go.
Or maybe my overall progress could be linked to my game profile or something, and I could start from whatever tier I want? *shrug*
Maybe at once point in my main progress, I could unlock something that could allow me to receive a drop-ship of ressources to get a quicker start in a new game?
Having access to coal and oil quicker without having to re-do the entire grind of the research tree would be a nice way to start a new game if I just want to experience the other maps.
But basically, right now, I feel more like starting a whole new base on the same game and same map than starting a new game from scratch on a new map.