No it is not. Even on my older N97 it was fun to play some games like Zuma Revenge. Yes, you are right, these games work best with small or zero GUI while playing. But this is possible especially with a touch screen.

I personally dont like the idea to have action games on a phone with touch screen controls. But I like to play puzzle games where you simply start an action with a touch of your finger. Another interesting idea would be to play adventure games where you move your character with a single touch, where you start conversions or investigations with a single touch of your finger. There is no messy HUD/GUI needed. And an adventure like this could have really nice graphics and could be 3d or 2.5d also.

Here is an example of an Android game (Angry Birds) where you try to destroy buildings (some kind of physics game play):



As you see there is only one single button to pause the game in the corner. A menu with more options will appear when you touch it. All the other game controls are just the screen and your finger. You scroll with your finger, you zoom with your fingers, you start the action with your finger and it really works.

And to be honest, these kind of controls are so intuitive and native that even my 3-years old daughter can control my phone. We installed some very simple painting programs on our phones just for my daughter. This shows easily that touching a screen is way easier to understand than using sticks, buttons or mouse.