I have very fond memories of Phoenix from childhood. The game was magic for me because it was so different from Space Invaders. It had so many levels and so many different kinds of enemies. It was bright, colorful and best of all, there was a boss fight! This was in the era before there really were boss fights so this was something unreal. And then there was the box and manual art. Insane. It was like looking at the coolest heavy metal album cover.
So it is hard for me to place Phoenix a lot higher on this list. Truth be told, it was #10 until about 5 minutes ago. But I was playing that game that is currently #10 and realized that I was fooling myself. Phoenix is really great, and I still love it, but it belongs here at #13.
Phoenix is awesome for all of the reasons I listed above. Three distinct varieties of game play. The first two levels are pretty standard, but then you get to the actual phoenixes and the don't die unless you score a direct hit! Survive those and take on the mother ship. That mother ship used to give me fits when I was a kid. There is so much variety in the base game that you can stay occupied figuring out the best way to survive each level.
If Phoenix has a weakness it is the lack of difficulty ramping. The difficulty does increase as you lap the levels, but not by much and not for very long. The difficulty tops out relatively soon and then you just play as long as you can. The mothership is really the only level that increases in challenge notably. That doesn't mean the game is super-easy, but it does put an early cap on how hard it will get.
The graphics are pretty solid. The color palette makes good use of shading and adds some complexity to the enemy characters. The mothership is big and the little alien inside looks smug in the safety of his pilot's chair. He is just asking to be shot.
Phoenix is one of the best examples of a vertical shooter that innovates and goes beyond the standard mold of what a shooter is. Space Invaders and Galaxian are fun, but you play the same screen over and over. Phoenix tells us there is more to see and do.
My Top Phoenix Score: 131,430 (I got on a roll. I honestly believe I can roll it. It's just a matter of taking the time to do it)