That's very good to know! I definitely got carried away a bit with designing ships and levels... That was definitely the most fun part of developing this game for me!
Some of the levels definitely throw you into the action right away, but not all of them are like that and some ships are better at handling that than others. I tried adding in a difficulty system that affects enemy spawn rates and # of lives, but I am thinking that if I continue working on this in the future the best way to go would be to add a kind of campaign that brings the player through the different maps in order from easiest to hardest. Is that something you'd be interested in?
As for the timer, I implemented it when I was working on the Survival level because without it the player could just wait out the clock in the ship select menu. I probably should have it be longer or removed altogether in the other levels though.