Kerbal space program but with tanks. As with most early access games it has a lot of potential, that being said it's already highly playable now if you want to design tanks. I personally have 170 hours in the game, the community is also pretty active which helped me get to such a high play time, plenty of designs to inspire your own creativity and challenges to do the same.

Right now I'm just waiting on another update to drop, then I'll drop my retired status.

This is a good colony sim, and I got over 100 hours of playtime treating it as such before I got bored.

That, however, isn't the main selling point, nor is it why I'm giving it 5 stars. This is the perfect video game storyteller, and ohoho when I understood that my enjoyment increased ten fold. Don't treat your colonists like cogs in a machine. No. They are people, with stories to tell, watch. Watch as Betty becomes the best constructor in the galaxy and makes legendary sofa after legendary sofa. Watch as you make a psychopath into a doctor and give them a minigun to mow down hoards of raiders from who she'll capture the survivors. watch as Barry flirts with a women the day after his wife dies tragically defending him. Follow the characters, follow their relationships, follow their journey's, that's what makes this game so fun. That's why I'm giving it 5 stars.

This game has a lot of potential. There is only a single dev and they have a full time job besides this, so I'm going to be patient and wait 5 years for this game to be finished.

That isn't to say this game isn't worth it now though, unmodded I would say there is 10 hours of gameplay here before you get bored. With modding I got up to 65, and since it has a steam workshop it is incredibly easy to do.
Just make sure you don't download something from several patches ago, they won't break the game but they also won't work as intended.

Great WW2 strategy, and out of all the paradox games I have played (so far) it's my second favourite.
The issue with it for me is there isn't much replayabillity, maybe you could get 300 hours out of this once you understand all three aspects of war (navy, army, air) but I never understood navy.
There's also modding but I haven't dabbled in that for a while because last time I checked a mod for this game the instructions included running a .exe file which I'm just not comfortable doing for a game with such a small following.

This was a game I really wanted to get into, however it just wasn't for me. Before I get into why I wanna explain why I still gave it 4/5 stars, because this is a good game, even I can see that even though I didn't enjoy it.

However if you're unsure about this genre I will tell you about my experience, and why I decided to retire from factorio. This game is a breeding ground for anxiety and stress, and your enjoyment of it will highly depend on your organization and planning skills. It will make you question whether or not you have ADHD.
You see in this game there are two key components. The factory, and the biters. The factory's main purpose is to construct science and allow you to progress through the game, the biters attack the factory and try to stop you. If you aren't fast enough with developing the factory the biters who constantly evolve will catch up and you will functionally lose. If you aren't organized enough it will be incredibly difficult to keep pace with the biters, that's why it took me 5 tries and 100 hours just to beat this game once. It may be the hardest game I've completed, and that's entirely because of my own incompetence.

Back to the stress, anxiety, and ADHD comment, whenever there is a task that needs doing in your factory you will inevitably be drawn to another task while doing the first. This happened to me for 4 hours once. FOUR HOURS. My factory was on the verge of running out of power for FOUR HOURS, but oh wait, sulphur productions a little low gotta do that, then I can scale up batteries... wasn't there something important I'm supposed to be doing?

That warning being said, you really can't know if this is something you'll be suffering from until 10 hours into the game, and it's not the most expensive game in the world, so give it a go anyway. Just be less stubborn then me and call it quits earlier rather than 120 hours in.