How do you know when a game is under you? Here we go.
Yeah, here we go...
I have never played/seen a game I would consider "under me", but this might be because I personally would see such a judgement as being in the realm of arrogance, and can generally find something interesting, if not likeable, about any system. Have there been games I've seen that aren't to my taste? Certainly. Some of them have even been popular games. (On the elecronic side of gaming, I really dislike the design of God of War, for instance.)
More often than not, games have elements that I like, and elements I'm not as fond of.
When you can enhance the game at your table outside the original author's intent.
I think this can be done with any game, good or bad. It's especially true with pen & paper RPGs, as most are essentially nonfunctional without a degree of creativity and imagination on the side of the player.
I know there are higher levels and you can personally make the game harder. Isn't that the time to create your own?
I'm not sure what you mean by that first sentence. It's not computing.
As for the second though, if you're disappointed in a game, I'd
encourage you to try making your own. It's a healthy exercise.
In my experience though, sometimes it's worthwhile playing under a design you're not 100% comfortable with or fond of. When doing so, try keeping an open mind and exploring the play experience for structures, ideas, and nuances that are engaging. You'll usually find some, and taking an interest in what works and what doesn't (Even what works for
other players, or things that work but are "diamonds in the rough") will both make you a better game designer, and a better
player. (As participating in pen & paper games almost always involves an element of active design.)
Sure beats sifting through hundreds of topics to find the right way to play. Or what stands out and/or disappoints you the most about this game?
What sifting through hundreds of topics does is give you a little sampling of a lot of peoples' play experiences and thoughts. That element of perspective (when applied properly) can be very useful for reasons I've talked about above.
When it comes to your last question, there are loads of threads on this board listing either standouts or disappointments in 4e, and I've seen several of both in my personal experience with the game.
I may come back and share some later, but for now I feel strangely weary.
Happy Holidays, and good, open-minded gaming to ye!