Street Fighter Alpha 3 is one of the best arcade ports ever...as long as you can get used to the GBA controls.
Now for the caveat: the controls. Obviously, SFA3 requires 6 buttons and the GBA is only a 4 button system. The developers worked around this by mapping two of the attacks to a 2 button push combo. That means to do a medium kick you must push A and the R Shoulder button together. You may map the controls however you like, but two of them are always going to require a double button push. SSF2:TR for GBA had a better setup where the length of time you held a button made the difference. However, my real problem is with the D-Pad. I had real difficulty making traditional Hadoken (Fireball) movement register reliably with the d-pad. Same with the Dragon Punch movement. Since these movements are the backbone of gameplay for just about every single character, it was a real problem. I played using both a GBA and a DS and ran into the same thing. SSF2:TR had an "easy" control mode where you could press the Select button and then perform the all the special moves by pressing simpler combinations such as F + Punch for a Fireball. It’s a real shame this feature wasn't included in SFA3 as it could have saved the entire game. There is a "Simple Combo" mode that makes it much easier to land combos and super combos, but you still must be able to perform the basic moves to create those combos. I am ashamed to say I simply could not. And I am a seasoned Street Fighter veteran who prides himself on his skill.
So in the end, SFA3 is like owning a Ferrari but not knowing how to drive a stick shift. The game itself is a near-flawless conversion of the arcade game and a real showpiece for the GBA. Unfortunately, the controls (or lack thereof) can quickly bring the fun to a grinding halt if you cannot get used to them. If you can't make the controls work for you, then I suggest you pick up Super Street Fighter II: Turbo Revival as its Simple Mode will make like much easier for you. However, if you manage to triumph over the GBA D-Pad and Button layout, then Street Fighter Alpha 3 will blow you away and provide you with hours and hours of Street Fighter perfection.