Astro-Dude

These are my modifications:

1. Complete Level2 redesign

2. New level added

3. Health only exist on level 2

4. An optional boss on level 3 that takes 10 hits to kill and  and moves faster than all the enemies

5. changed music

6. green doors indicate the end of a level

7. Scores don't matter. Just survive the level

Credit:

Created by Paul Campbell