Jet Impulse/Walkthrough

Prologue 1
Destroy all units.

Prologue 2
Destroy all units.

Stage 1
Destroy all air units first.After the cut scene, destroy the left propeller and the right propeller on the tanker. If you try to pull another Exxon Valdez by blowing up the ship, you will lose.

Stage 2
After destroying all units, you will have trouble dealing with the reinforcement("Crimson"). After the cutscene, run. Ignore the enemy.

Stage 3
Concentrate on the ground units first. If all your team's ground units are destroyed, you lose. Afterwards, fly towards the enemy's base (indicated by the white dot on the radar) while destroying all air units in the way.

Stage 4
Again, just floor the throttle and run.

Stage 5
After destroying the boats, a submarine will appear. Since there is a time limit, concentrate on the submarine.

Stage 6
Destroy the air and ground units, then the air-dropped crates. When the air reenforcement arrives, you only need to destroy the jet in the middle (the one labelled "White").

Stage 7
After destroying everything, 3 minibosses will appear. After that, 2 more minibosses will appear. You only need to destroy the black plane.

Stage 8
Destroy ground units first, then the giant flying object. After blowing up the giant object, run.

Stage 9
Find your downed soldier (indicated by the white dot on the radar) and fly near her to trigger a cutscene with a flare, then destroy the enemy.

Stage 10
Destroy everything, concentrating on the sea units first. You can only shoot at the submarine when it surfaces.

Stage 11
Destroy everything.

Stage 12
Follow your team to the enemy's stronghold. Destroy the air and ground units.

edit from this vague guide:

Follow you're teammate at a low altitude stick to the ground if possible, after you're teammate turns there should be 2 radar towers to you're left flank and right flank; keep alternating from both targets using the X button, make sure you maintain a minimal distance of 3000+M; at the same time try to maintain a altitude of 1000~1300M; soon after you should be seeing a open field lower your altitude and lay wast to all.

Stage 13
Destroy all units. Some ground units will be in the valley. Using bombs will make it easier.

Stage 14
The enemy will use electronic jammers. Note the location and range of the jammers on the radar and destroy them by shooting at them from the back.

Stage 15
Protect your base by destroying all units. Concentrate on the ground units first. After the cut scene, destroy the 3 bridges. You don't need to shoot at the tanks on the bridge because destroying the bridge will cause them to die as well. Destroy the remaining air and ground units. An aircraft-carrier-on-wheels will appear. When you destroy it, the enemy general will try to escape. Shoot it down to win.

Stage 16
Keep below 1000m at first or bad things will happen. Destroy one plane first. Follow the river and you will eventually meet your second target. After the mission update, you can fly above 1000m to destroy everything.

Stage 17
After destroying all the jammers, the final boss will appear. Destroy all the laser cannons on the mothership first. The weak spot on the mothership is the grey circle on its bottom. The best way is to approach it from beneath. The evil dictator will try to escape when the mothership crashes. Shoot it down to win.