successful Before writing the ideas, I want to mention that the science gathering in KSP is flat (other than the breaking ground science experiments, but that is an extra for the game)
By "flat" I mean that there isn't a lot going on for each experiment. In KSP (without DLCs), you just press the "give science" button, and in, at most, two seconds (other than the EVA science pack), you have extra science. Now you cat get it back to Kerbin, or transmit for less. With the temperature, pressure, Goo feelings (and some more) on and around Ike, you can unlock the all new 5m fuel tank for first stages. Having only one number to unlock the tech tree with makes it kinda bland. Just going somewhere you haven't been in that save, and pressing the "give science" button for the same experiments until you can unlock what you want.
(now for the ideas)
- Have multiple science point types: In the tech tree there's a "spectrum" of science types: for technical stuff (for probes, more science experiments, better antennas, etc), for Kerbal stuff (command pods, habitation modules, and other stuff that Kerbals use, etc), and for propulsion (engines, fuel tanks, etc) (if the fuel and engine systems are complicated in KSP2, these could be separated into two types, but maybe not worth it).
- Each science point type is gathered in a different way: the technical type can be unlocked trough scans, like the magnetometer, atm. analyzer, seismic scans, gravity scans (the KSP2 equivalent of those). The Kerbal type can be gathered with temperature and pressure scans (on that note, being able to scan the pressure in space, especially around planets without atmosphere, multiply times and still getting valuable science doesn't make sense), and especially successful flights with Kerbals in different environments. The propulsion type can be unlocked, reasonably, by using them, in different environments, with more expensive/complicated engines giving more points.
- Data transmission (and processing?): I think data should send full science if it sends numbers (temperature, pressure, etc.), but with more complicated experiments (eg. atmosphere analyzer), it should send less than full, and like in KSP, you can transmit less science the worse your connection to the KSC is. For samples and observations, you shouldn't be able to transmit data at all (the breaking ground mystery goo ground experiment cheats since it has a camera). Data from a mobile lab should be sent at 100% (after the lab multiplier is added), since the scientists inside have realistically watched the image of goo enough to declare that "the goo feels at home here". Of course the Kerbal science type should only be collected back on Kerbin. Maybe an engineer and a lab could go together to be able to transmit this type of data (engineer to see how the vessel disintegrates, scientist to analyze). And for the propulsion type, you still need to get the science back, but based on the complexity of the engines and experience of engineers on board you can transmit/get more science when recovered.
This is what I think I would like to play (now, just because I ranted about this, doesn't mean it's good or that even I'll enjoy it, but I hope the ideas are good)