yes, a nice looking game having a good video could be boring after playing with it 5 minutes.

my main interest is game AI, maybe because my favourite game genre is strategy, where you have to rather think and organize than shoot. a good and addictive game gives you reward only if you are really good, or more exactly if you can improve your skills continuously, and it needs a very-very fine tuned game and enemy AI system. or make multiplayer to fight against human players, but it requires a server to maintain and also some network programming skills.

Esenthel provides you MMO solutions, basic navmesh pathfinding, a nice editor, useful game classes, quality rendering and effects, but it is not a toy, it is rather for making quality games, and requires advanced programming skills. Unity and 3DGS is good for toying too (beside the possibility to make good games of course!), but you can build your game onto example projects source codes, just have to read a lot and tweak them, it requires to go through only a few C++ tutorials like I did, with some basic programming knowledge (of Lite-c or UnityScript) it could put you into the right direction.