I'm not sure what version you played but I've been updating it constantly and am currently working on something. I think in the version you played the upgrades were applied at different score levels so for example dual shot at 1400 and missiles at 2000. (The version I am working on now has an upgrade menu instead, people seem to like choosing their upgrades rather than being given them.) I don't feel that the enemies move too fast however, I believe that is a part of the challenge. The Idea I had was that you have to kill enough enemies to keep up with the enemy waves in terms of upgrades. I'm not sure how to answer the last question lol its round and purple its a weird alien ufo I wanted it to look as such.