Do not worry about catching bombs using the top bucket.You can use just the bottom two buckets without problems.
When the hundreds portion of your score is in the 900s, lose a bucket if you have all three of them. The game will resume at the previous level, gaining that many more points at no additional difficulty, and will have your third bucket again after passing the next thousand mark.
It is possible to score 999,999 points, which is the maximum amount. Follow the Mad Bomber as he moves, carefully duplicating his movements exactly in order to arrive at each latitude a just him in order to catch all of the bombs.
When you score at least 10,000 points, the bomber will be surprised.