Visually, Puzzler Mind Gym 3D has a leg up on the older games as you can play it in 3D. For those of you who love the 3D feature, that's a huge bonus. If you're not big on 3D though, for the most part, you can turn it off and it doesn't really affect the puzzles or your ability to play them, which is really nice because some days your eyes just don't focus on 3D after hours of playing! I do like that all of the puzzles have very easy to distinguish characteristics. If it's a number, then they are easy to read. Items are easy to pick out and things stand out well from the background. All these things are very important for a successful puzzle game.
The audio is nice, but not absolutely necessary to the game. The background music will help you tune out outside noise distractions without distracting from the game, but if you happen to want to listen to whatever you want, you will pretty much be ok doing that. You will get a beeping when your countdown timer is almost out though, and that is handy.