Silkworm/Wave 1

The first stage of the game is obviously easier, but there's still plenty of surprises and the stage starts with an early attack.

Arcade
In the arcade version, enemy attacks appear at the following times:
 * 0:01: Four helicopters on the top, and one ground missile launcher.
 * 0:06: Four helicopters approaching in a spread, shortly followed by three ground missile launchers, finishing with four helicopters approaching in the middle.
 * 0:15: Ground installation, followed by five helicopters spread in the middle, and one tank.
 * 0:20: Eight helicopters in the middle, one landmine and one tank.
 * 0:27: Four helicopters, one land mine.

If you've generally been destroying most targets, the snakehead should arrive by now.


 * 0:30: One helicopter.
 * 0:40: Five helicopters, one of which attacks from behind. A ground 3-way missile turret also appears.
 * 0:48: As you reach the bridge, four helicopters in a wall, a silo, a tank and another silo. Eight tanks are then air-dropped from above.
 * 0:58: Indestructible missile launcher on the bridge, and two slow helicopters above.
 * 1:03: Land mine, and four helicopters from the middle going to the top.
 * 1:06: Five helicopters, one attacking from behind, the rest from the front. One land mine.
 * 1:14: Two slow helicopters on top, landmine at bottom. Leads to two AA tanks, 10 helicopters from low to top, two missile launcher turrets
 * 1:25: One helicopter that shoots in eight directions, above a land mine.
 * 1:30: One helicopter on top, three more from low to high.

The first boss is rather feeble, firing occasional missiles, and two regular shots in series. The mines it drops only serve to distract the jeep.