I've been working on Metropolis 1998[1] for +4 years now. Custom C++ engine built with a modified version of SFML 2.5 and SQLite.

Creating my own engine was both a personal and strategic decision for me. I was really worried about running into performance issues with generalist engines, and I did not want the friction of working with someone else's mental model. Pretty sure that friction would have caused so much burnout for me. There's also the long payoff of operating in an environment that you understand top to bottom.

I ignored all the advice about making smaller games first, creating an engine first, etc. Metropolis 1998 is my first game and so far it's working out just fine. But your mileage will vary.. I started development with 10+ years of software experience and fond memories of Rollercoaster Tycoon and SimCity 2000/4.

I only add what I need. There's no level/scene editors (outside of the game being one itself :P ). No scene graphs. Shaders are coded by hand. Right now the entire game is about 45MB.

[1] https://store.steampowered.com/app/2287430/Metropolis_1998/

Curious how long you spent on the "engine" vs just writing the game? Based on the stuff I see on Steam you're pretty far along. I see it's Windows only which makes sense for your goals (and honestly seems very easy to run in a VM.) Was it easier to target and test for a single platform?

(Also thanks this is exactly the kind of game I'm into.)

Your screenshots look dangerous i.e. I'm constantly seeking some hiding aliens there

Looks fantastic! Growing up on RollerCoaster (+Transport) Tycoon and SimCity myself, this is exactly the kind of project I'd dream about building, if only I had your dedication!