The Fourth Encounter

The Fourth Encounter is a fixed screen shoot 'em up for one or two players.

As the title might indicate it consists of four stages with different enemies in each. They can be played through in one go, or the player can pick any of them without completing the previous ones.

The enemies in each stage has their own tactics in taking out the player. In the first wave the enemies try to crash into the player, while the aliens of the second and third stage fires at the player. The player ship can only move along the bottom and shot up against the enemies. The fourth stage is the one that differs the most from the other stages. Here the enemies follow the edges of the screen and shoot in towards the player who now can move around the screen freely. What's more, it's also possible to shoot in two directions, both up and down. The player has five lives and it's game over when they are all lost. Three different skill levels can be chosen from.

Source: https://www.youtube.com/watch?v=eKHhZPSNYwY