Thexder/Gameplay

Thexder Controls
As the pilot of Thexder, you must master all of the controls in order to successfully guide Thexder through all 16 stages. Since Thexder has two modes, it is important to understand each set of controls as well as how to switch from one mode to the other. Your method of input (joystick, gamepad, or keyboard) is dependent on what system you are playing on, and which options are available to you on that system.

Robot mode

 * Joystick/D-pad/Arrow keys: Press left or right to direct Thexder to run left or right. Press up to make Thexder jump.  Hold up to make Thexder jump higher.
 * Transform: Press down to make Thexder transform into a jet.
 * Button 1/Space bar: Press this to make Thexder fire his beam rifle. In robot mode, the beam rifle will cycle through all available threats that can be targeted in Thexder's current orientation.  The beam rifle uses up 2% of your available energy per roughly 30 shots.
 * Button 2/Shift key: Press this to activate Thexder's particle barrier. The particle barrier consumes 10% of your available energy, and cannot be activated if you have less than 10% of energy.

Jet mode

 * Joystick/D-pad/Arrow keys: Use this control to direct Thexder to fly in any one of eight directions. Thexder will automatically rotate through a turn if no other option is available.  As a jet, Thexder cannot remain stationary.
 * Transform: Thexder will transform back in to a robot if he hits a wall in the current direction that he is traveling, or if, while Thexder is flying horizontally, you press the opposite direction from the one that he is currently facing.
 * Button 1/Space bar: Press this to make Thexder fire his beam rifle. In jet mode, the beam rifle has no choice but to fire in the direction of Thexder's current orientation.
 * Button 2/Shift key: Press this to activate Thexder's particle barrier. The particle barrier consumes 10% of your available energy, and cannot be activated if you have less than 10% of energy.

Thexder's shield
The choice between using Thexder's shield and not using it is an important aspect of the game's strategy.
 * Reasons to use the shield: The particle shield is easily one of Thexder's most important tools for survival, even more so than his beam rifle. For the cost of 10% of energy, Thexder's shield absorbs substantial amount of damage, and also delivers damage back to the enemies that are colliding with you while the shield is active.  This makes the shield a powerful tool, one which can keep Thexder alive for much longer than he could without the shield.
 * Reasons not to use the shield: Energy is a precious commodity throughout the game. It can be hard to come by in large quantities.  The maximum amount of energy that you can store is a valuable attribute to raise as high as possible (to a maximum of 500%).  While you are awarded additional max energy for every level that you clear (10%), you earn substantially more (30%) if you never activate your shield once in a level.  You will also be awarded an additional 100% to your energy meter.  Therefore, if you can survive a stage without a shield, you are rewarded tremendously for the accomplishment.  As you get closer to a maximum energy count of 500%, you may opt to use the shield more often, but you will forfeit the 100% energy boost at the end of the level.
 * How to decide: In general, as you play Thexder, your ability to survive each stage will increase with practice. If you are visiting a level for the first time, it is recommended that you rely heavily on your shield until you are familiar with the layout, and know where to find energy producing enemies.  Once you are comfortable with the level, and know how to maneuver through it with minimum damage to Thexder, you may opt not to use the shield in order to receive both the 100% energy bonus and the increased 30% max energy bonus, which will enable you to stay alive a lot longer in later, more difficult stages.
 * Important note: In at least the Apple IIgs version of Thexder (and possibly in other versions, too), if you use the shield on any given level and then proceed to the next level, you forfeit the 100% energy bonus not just for the level you just completed, but for the rest of the game, i.e. for every subsequent level even if you never use the shield again!! It is therefore a very good strategy to never use the shield when you intend to complete any level - only use the shield for practice.

Planet Inhabitants
Enemies can be categorized into three groups; Enemies that primarily attack, energy providing enemies, and enemies that are generally hidden and need to be shot at to reveal.

Attack Enemies
Attack enemies range from mild threats to extremely aggressive. Many of the attack enemies like to swarm around Thexder and attack him from multiple sides to drain his energy very quickly. Some of the enemies listed here will provide Thexder with a nominal amount of energy, but a majority do not. As a result, these enemies should only be fought if they are blocking you from reaching an exit, or an energy producing enemy.

Energy Enemies
Enemies that can provide Thexder with energy should be sought out and destroyed as frequently as possible. Not only do they provide Thexder with a good amount of energy, but many of these enemies, including the Bell, Bellmeta, and Centibeet, can raise Thexder's Max Energy. It's a good idea to go out of your way to find them as long as the passage to them is safe. If you end up losing more energy than you can get back, it's generally not worth seeking them out.

Hidden Enemies
Hidden enemies are generally unseen until you shoot at their location. Thexder's targeting computer will still acknowledge their presence even if you can't see them yet, making his robot form excellent for discovering hidden enemies. Some hidden enemies like Bino, the Flower, and Yamato are stationary, while others like the Eye, the Geisha, and the Tophat (which can be seen a few times), will stick to the ground or ceiling and attack. All hidden enemies provide Thexder with an appreciable energy boost and a sizeable Max Energy boost.