The main objective of the game is to guide Spaceman Dan around the environment collecting all of the fuel. When all the fuel has been collected, the doors of his ship will open and you can then guide him back to the ship to successfully complete the mission.
Spaceman Dan can be manoeuvered by either a joystick/controller in the "left" port or by the direction keys listed below. He can move left, right, up or down, once he starts moving he wont stop until he strikes another object, therefore care must be taken to avoid him flying off into space as this will result in the loss of a life.
An oxygen meter is constantly counting down throughout the mission, if this reaches empty a life will be lost. Strategically placed oxygen cylinders are found in some of the more complicated missions, collecting these by running into them will refill Spaceman Dans oxygen supply.
Some missions contain one or more space droids. The player can cycle control between these and Spaceman Dan by pressing the fire button (B button on a Megadrive gamepad) or the 'P' key. The currently controlled character is highlighted by the sparkles around it. The space droids obey the same rules as Spaceman Dan with regards to movement and loss of life, but they can be used to gain access to parts of the environment that would otherwise be unreachable by strategically positioning them so they can be used as barriers that can stop Spaceman Dan to align him with gaps or collectibles.
Satellites are found in the some later missions. If Spaceman Dan or a droid bumps into one of these they will stop moving and their motion will be transferred to the satellite. Similarly, if a moving satellite strikes another satellite, then it will stop moving and its motion will be transferred to the new satellite, allowing cascading movement of satellites. A moving satellite will only stop moving when it strikes another object. As with Dan and the droids, care must be taken not to knock a satellite out of the environment.
Additional perils appear in later levels in the form of electric arcs if Spaceman Dan or any of the space droids are struck by these this will also end the mission with a life lost. Satellites are unaffected by electric arcs.
Finally, some later missions contain coloured blocks, either red or green. These are unlockable barriers. When these are present in an environment there will also be similarly coloured "key" objects. Placing Dan or a droid on a key object will cause any walls of the same colour to disappear. Moving Dan or a droid off the key will cause the wall to reappear. These are only found in missions containing Dan and at least one space droid as one character can be used to unlock walls allowing the other through while the barrier is removed.
Galaxy of Error can be played with any of the following control options;
By default the ZX Spectrum Next is configured with its left joystick port set as a Kempston compatible port. This works with a regular Atari style joystick with a single fire button and it should be left this way if you're using this type of joystick to play Galaxy of Error.
Galaxy of Error also supports Megadrive gamepads, with the following features;
The following slides show the steps to take in order to change the port configuration on your ZX Spectrum Next.