Very cool for a single tweet! The enemies look pretty faithful. Enemies going all the way across the screen and speeding up are great. That last enemy was pretty tough to hit!
Thanks.=)
I was working on a full-fledged version of Space Invaders with enemy fire and destructible barriers meant to fit in two Tweets, but didn't manage to fit it in the character limit by the deadline. It's currently about 100 characters over the limit, but hopefully sometime I can figure out how to shrink it the rest of the way.