There is only one key to press. Use the up arrow on your keyboard to provide thrust upwards. When you don't apply thrust the ship will fall under gravity. A regular tapping of the key is the most effective way to achieve level flight.
This kind of game has been around a long time on many platforms. The side scrolling is achieved by cloning a single strip of landscape over and over. Each step of side scroll is triggered by a broadcast the all close of the land are receiving. Each time they get the signal they step to the left, creating the side scrolling effect. To avoid creating too many clones, the clone which goes off the screen on the left deletes itself. Different difficulty levels are achieved by using 'costumes' of the same sprite with reducing space to fly the ship. The game stores hi score in the cloud. Restarting the game after a collision is a little difficult to follow in the code. A self destruct signal is sent to all the clone sprites and a new 'family' of clones is started again.
