UFO

The UFO is an enemy in Swamp Attack.

It only appears during unique UFO levels, which are marked by it's signature icon, being present on every 5th level of each episode.

Abilities
The UFO will confiscate many your items at the start of the fight. Known examples include all the Explosives and ammunition for all your weapons except for the Shotgun/Double Shotgun.

It often flies around the battlefield and if shot, will disappear and drop a random item which can range from any of your stolen items. In the case of weapon ammunition, it will drop a full magazine unit (equal to ones you can buy in the shop). In the case of an explosive, it will drop one each time and your explosive load out affects it so if you've equipped the A-Bomb, it can drop one in the fight. All items keep their upgrades.

If not tackled, it will despawn but another one will soon respawn.

After the end of each fight, all your stolen items are returned to you, while ammunition gained in the fight will not be kept (even if it is not from the UFO).

Trivia

 * The UFO cannot damage the house nor does it support the enemies directly.
 * Rarely, multiple interactive UFOs can spawn at the same time.
 * At the end of the level, regardless of your progress, it will always end up crashing behind the house, dragging a black smoke trail.
 * This happens whether the interactive UFO on the screen is present or not.