ok, so a few ideas/suggestions
1:remove the time limit. being locked out of the game after day 20 isn't fun. i think there should be an option to continue with an "endless mode" with the disclaimer that any saves made past that point might not work properly for future versions. theres content and things to do that aren't time locked but still take time to do that having room to breathe and do stuff at your own pace would be very beneficial. (especially when trying to grind for expensive things)
2:rework the persistent debuffs. either make the fee to fix them much cheaper, make them temporary, or turn the event that gives you them into a combat encounter that only applies them if you lose.
3:make buying parts from the synth lover shop cheaper, or make selling parts there more lucrative. even a mint condition part only sells for 400 credits. making them about 30% cheaper than they are right now might be reasonable, and a part at 100% condition should sell for at least about 80% of what you can buy it for.
4:this one might be a bit ambitious, but i think it would be cool if starting with a different purpose gave you different parts. for example, the battle bot might start with parts that are more durable but are also uglier. and the sex slave might start with parts that are more beautiful but also more fragile
5:this one is very ambitious, but i think part condition is a bit underutilized. i find it a bit odd that someone would design a robot (especially a battle bot if you chose that background) to feel physical pain the same way a human does, especially when it seems to not be proportional with actual damage. i think a system where individual parts can be damaged and disabled in combat would offer a lot of depth. my current idea is something along the lines of this. every part as well as your core would have two stats, stability and integrity. integrity is pretty much like health is currently. wear and tear that needs to be repaired. but stability would be a sort of replacement for pain, representing temporary dislocations and glitches that may impair a parts functioning without necessarily being lasting damage. integrity obviously requires repair to restore, but stability quickly recovers when out of combat. most attacks would target one or more parts and reduce their integrity and stability. when a part loses all it stability it becomes disabled and temporarily loses function. disabled eyes would reduce accuracy, disabled arms weakening attacks, disabled legs making you unable to kick, etc. core integrity and stability are basically your main health meters. if enough parts are disabled or have low stability then all further attacks will start to reduce your core stability, and when that reaches 0 you collapse and are forced to surrender. if enough parts are broken or have low integrity then further attacks will start to reduce your core integrity, and when that reaches 0 you enter critical condition and have to be rescued by the clinic.
if that last one isn't possible or doesn't fit with your vision of the game then that's okay. i imagine it might be difficult to program so if you want to keep the current health system that's understandable, but the first 3 i think would do a lot to improve the game.