What is depth?
This word, misused countless times in my opinion, still has yet to be
properly defined. How do we determine whether or not a game has
depth? One example I'll start with is fighting games. In my opinion the
Dragonball Dudokai series (including budokai tenkaichi, not an official
sequel) is a relatively simple game. I sat down and read through an FAQ
on how the combat system worked, played the game and faired well
enough. Much more needs to be explored, yet I feel Tekken, Virtua
fighter 4: Evolution, Soul Calibur 2 (to lesser extent, bumped into plenty a cheeser) to be far more difficult to grasp. Don't think I forgot about Streetfighter and the other 2D games. I selected the titles I consider myself skilled in.
Tekken is the game I excel in, but still consider myself a beginner. When playing Virtua Fighter 4, I am a novice. In Soul Calibur, I'm strong. But there are a multitude of variables to consider while playing these games.
Ring Outs
Counters
Buffers
Control Scheme
Players Ability
Difficulty
AI
Balance
Learning Curve
Abusable Moves
Reaction Time
I seek others logical input on this topic, speak from experience.