1. Castor and Pollux' Slaves are different colored because the Slaves are nearly the same size as the Gemini Wing ships. If they were the same color, people will confuse the Slaves with their own fighter
2. We have other options to make the game easier for the player: changing starting rest lives and bombs, for example.
3. Tarma and Eri will be represented in a second Metal Slug fighter, likely the Slug Flyer jet.