2.1:
- Hold a direction for a second to repeat move
- One new enemy for each colour
- Some enemies no longer move over each other
- Blue Chasers no longer stack
- Different coloured enemies now have unique sprites
- Plain items now sort above red items
- Scroll wheel now switches selecte item
- New boss added
- Secret late-game stuff


2.0:
- Ported to Gamemaker: Studio
- Possibly other changes


Everything before Studio wasn't documented.