Excellent! This was a great memory/coordination game! I was pretty underwhelmed at first, but when the ENTER key came into play, the game clicked. Even realizing how many missiles go into a Super-missile of a certain color is important in tactical planning. The ending "message" was so cool that I had to look it up on Google to make sure it was actually true! I won't say anything except: the title of the game may have more than one meaning...
I wanted to complain at first that the numbers were too far apart... that is, having to switch between 3 and 0 was difficult, and cheating by using the Numpad was actually even more difficult. However, by the end of the game, I was used to the mechanic and having to move around so much just felt like part of the challenge.
This is a game that you get better at as you play. Because the enemies are randomized, you can't just memorize the pattern. If you want to win, you have to practice for a while and learn how to survive by memorizing which key corresponds to which number --because knowing off the top of your head will help you live longer than checking the bottom of the screen repeatedly-- and developing a method for switching between 10 number keys while using the arrows, the space bar, and "Enter" at the right times. The final boss seems easy at first, but after three rounds... well, I won't spoil what his final trick is.
Not too many issues. You might want to shorten the first level. It went on a bit too long and you might lose some players who see simple graphics and bland gameplay and think, "Well, this sucks," without realizing what the game is really about.
Occasionally, I had a small problem with the arrows and space bar not responding as quick as I needed them to, but it waned with practice and it didn't stop me from winning.
Also, you might want to consider adding some music or some sounds to liven things up. On the other hand, considering how much concentration the game takes, there was something very "Zen" about playing it in silence.
This was fun, challenging, and for a variety of reason, I felt smarter when I finished. You're off to a great start. Can't wait to see more games from you!