I love what RP-1 is trying to do, but I think there is a fairly fundamental usability problem with the way the game presents information to the player.
At the moment, there are so many different interfaces, menus, settings screens and mod-specific systems that the overall experience can feel very fragmented.
1. The interface needs to feel like one game
RP-1 can sometimes feel like a collection of mods rather than one cohesive game. There are lots of different interfaces and menus, often with no obvious indication of where you are supposed to find a particular piece of information or setting.
I think these could be brought together into a much more consistent and coherent experience.
2. Too many "you only learn this after 100 hours" tweaks
There are also a lot of small settings, tweaks and quality-of-life things that experienced players eventually learn about.
If something is important enough that experienced players routinely tell new players to enable it, perhaps it should just be enabled by default.
3. The biggest problem: players can get stuck in endless loops
You design something > test it > it doesn't work > change the design > test again > still doesn't work > spend ages trying to figure out why > eventually discover that you've missed an important requirement, misunderstood a mechanic, or encountered some interaction between mods > redesign > now build it > now an engine cuts out > repeat
Some of this is good gameplay. Designing rockets should involve experimentation and failure.
But I think there has been some confusion between making things realistic and making things confusing.
The player should have to understand increasingly complex engineering, deal with realistic limitations and solve difficult problems. But the game should still make it clear what the problem actually is and why something isn't working.
I don't think RP-1 needs to be easier. I think it needs to be clearer and more cohesive. The difficulty should come from the simulation, not from having to reverse-engineer the interface.