Pretty much all projects I worked on; first person, third person and twin sticks. The problems are not in the engines capabilities, far from it. But in the tutorials and documentation that are incomplete or hard to use. The community is also a lot less involved and helpful compared to UE4 or Unity. These are things that really do matter, especially for engine first timers. Another thing is the general workflow and/or UX, and especially the content pipeline can be a major pita. Much of this is obviously subjective but you see these type of sentiments everywhere, and it shows in the way the engine is adopted.