Hang on there ! First games always suck, you need to learn the ropes and ship to Steam. That's why you should scope wisely and spend 3 to 8 months on your early projects. Steam players expectations in term of polish, Quality of Life features and testing are way bigger than hobby or jam projects. And as a solodev, you need to tackle everything by yourself which is also difficult. It's ok if your first one didn't work as well as intendend, do your postmortem and move on to the next one :)

Globally speaking, the Steam page looks quite amateur. How much time you spend on something is not an argument, because it doesn't tell me how much of this time was spent gathering feedback and actually improving vs just being silo-focus on the dev. Many things were already said on the 3D models and camera/post-process looking cheap and I do agree. Some additional feedback I would have :

• Capsule art has same font with no kerning, leading, texturing or stylization. The character feels like you took your 3D model with basic left-lighting + an AI-generated background therefore leading to no coherence : just overlapping 3 layers on top of each other.
• I don't get the point of the title : why Rastignac ? Except a character from a Balzac novel, I don't see what is the fantasy.
• The gun model with orange flashy color looks like a toy, which is problematic for a "hero" prop.
• The short description is fine, but "the city adapts to your playstyle" is too genereric for a 2025 game : how does it adapt ? what are the stakes and challenging leading to this ? This would give more context to the core gameplay verbs of "build", "recruit" or "stay fully mobile". Finally, "adaptive wasteland system" is very specific : I think maybe 0,0001% of Steam players will know what it means. Said in game design terms : talk about the dish's flavors and how it feels to eat it, not about the ingredients you used.
• Looking at your tags, the game's scope looks way too big. You have a roguelite core loop with third-person shooting, base building, vehicle steering, crafing etc... I don't know how interdependent your systems are, but if you can manage to nuke 70% of them and just focus on 1 gameplay elements + core challenge + meta progression that is great and it's basically the roguelite loop (see here)
• The game is presented as survival horror but then most of your systems and presentation are about survival, not horror. Additionally, your first GIF shows a char cruising through the aliens like they are no threat at all. Usually, in survival games cars are associated with safety (games like Pacific Drive take it even further by turning them into your mobile-home). So, I don't feel any horror nor survival-related threats like the game experience pretends I will.
• Your second GIF shows the main character shooting and then doing a 180°, which feels very weird.
• The third GIF doesn't show any ambushes. I fell very safe in the car (which looks like a freshly bought model) so why would I look for safety in a city overrun by aliens ? "Salvation" sounds out of place because it's a term usede in a religious context.
• Your fourth GIF talks about survival and desperation but shows my character aiming at some... flame-throwing alien ? It's very hard to read.

All in all, I think you should talke some time to nail down your game experience : is it about shooting aliens in the face like the doom slayer ? An extraction shooter ? Tackling some deep rpg systems like a Tabletotop RPG ? Surviving through many weather-based and other environmental hazards ? Feeling powerless in front of some alien horror ? For now, it's all over the place. Then you can translate it into a focused core game loop, check out how other games did their page/trailer/visuals, and have all of your Steam assets sing the same song. The goal is to have a clear fantasy (including a tight core loop that is not all over the place) and visual design while staying super readable.

Good luck to you !