Kerbal Space Program

It's a fun game but a tremendous waste of potential and a case of the incompetent devs. I played it since the first release in 2010 (or was it 2011?, in any way, one of the first Early Access games after Minecraft) and the devs took so long to implement simple features that had been modded in for years that I wonder how they even got it released as 1.0 (that update mainly added female Kerbonauts). I gave the game 4.0 cause I really have spent a lot of time with it and I love the idea behind the game, but some other game in the same situation I would have given way lower a score (like Minecraft, for example, which I never really enjoyed but played it around a similar timeframe). I just hope this spawns more realistic-space-physics-sims of some kind because I feel a lot can be done with just that concept and adding something on top.

All in all, I found all my enjoyment in the sandbox mode making my own goals. I have no idea if the campaign mode is balanced at all since I never really got into it, but if you want a challenging game that's totally unlike anything else and don't mind just doing sandbox stuff in it, you can easily get a 100 hours worth out of it, especially with mods.