What are missions
Missions are a new type of feature that was added in Star Warfare 2: Payback. Missions are the main goal of player levels (excluding Bosses and Explore). Missions usually have one goal or more and can range from Easy-Brutal. A level cannot be passed if the player does not complete the main goal. Missions can be seen in the middle of the screen in top of the player. Missions can grant huge gold bounties upon completion. Missions will usually repeat themselves in other levels (For example you will have to survive in stage 1-2 and do the same thing in level 3-1) but depending on the difficulty and which level you are on the missions will grant different gold. Missions cannot grant mithril however sub-missions will. Completing a mission will grant you a star and if you have completed any other sub-mission you will also gain the stars from the sub-missions.
Sub-missions are "bonus" missions that appear in every level that has a main mission. Sub-missions are very different from regular Missions but both act similar. Sub-missions do not grant any gold, instead they will grant a small amount of Mithril upon completion. Sub-missions will also grant 1 star when completed, when all sub-missions are completed a treasure chest full of Mithril will be awarded to you. Sub-missions will not grant any stars if you do not complete the main Mission. Do not overlook sub-missions during a level. They can give you a lot of Mithril and can grant a reward enough for you to purchase something that costs Mithril. Sub-missions are usually harder then the Main-mission with quests such as move less then 400 yards, vehicle health above 50%, defeat 60 aliens with (weapon) etc. Like missions sub-missions are increasingly harder if you are playing on heroic.
List of missions and sub-missions. Do not read further if you do not want spoilers. You have been warned.
Stage 1-1: Explore 4 Areas (same quest in Heroic)
Stage 1-2: Survive for 2 minutes (4 minutes in Heroic) Hover over for spoilers
Stage 1-3: Breach the area; kill 75 aliens (150 in Heroic)
Stage 1-4: Protect the crystal for 2 minutes (4 in Heroic)
Stage 1-5: Blow up 2 targets with bombs (4 in Heroic)
Stage 2-1: Explore 4 areas (Same quest in Heroic)
Stage 2-2: Protect 2 defense systems for 2:30 minutes (4 minutes in Heroic)
Stage 2-3: Defeat 50 aliens near the Legacy Building (140 in Heroic)
Stage 2-4: Defend the vehicle to the location (same quest in Heroic)
Stage 2-5: Find an Escape (same in Heroic)
Stage 3-1: Survive for 180 seconds (5 minutes in Heroic)
Stage 3-2: Protect Lt.Bill to the destination (same quest in Heroic)
Stage 3-3: Attract and kill 3 Elite Stalkers (4 in Heroic)
Stage 3-4: Defeat 100 Aliens with Lt.Bill (160 in Heroic)
Stage 3-5: Charge the weapon to destroy the portals (same in Heroic)
Stage 4-1: Explore the core (same in Heroic)
Stage 4-2: Defeat aliens in two areas (same in Heroic but more aliens need to be killed)
Stage 4-3: Seduce and kill all Elite Aliens (same in Heroic but you will need to kill more Elite Aliens)
Stage 4-4: Explode the core (pretty much the same in Heroic)
Stage 4-5: Escape the core (same as above)