Sky Force Reloaded

The ambulance is one of the unlock-able ships. You first need to collect the 5 ship pieces for it. This collecting is completely random unfortunately so when you get it will be tough to estimate.

The Ambulance has a few differences than your classic fighter:

1) Collects Civilians faster than normal - this really doesn't affect your overall play throughout

2) The blaster fires in a fan. You will have a few shots directly up and some to the left and right offset by roughly 30 degrees.

In general, the first condition doesn't mean anything. If you want to use the ship to help in collecting civilians, it might make that medal easier, but in general that isn't our goal here.

Change 2 can be annoying. The fanned out shots are a lot weaker. You can hit some new spots as a result, but the lack of focus for your attack makes taking out enemies a lot slower at times. This can be felt when stronger basic enemies and bosses are on screen.

Keep in mind, for this achievement you only need to beat all 13 of the base levels (not B1 and B2). Additionally, beating them on Normal is sufficient. Additionally, the medals you earn doesn't matter either. All that matters is that you go from the beginning of all 13 levels to the end and see the "Mission Clear" message.

You can check your progress by going to the "Collected Parts" portion of the main menu. Any ship you have all the parts for will show you which missions you have completed at this point for each of them.