Editing Commander Keen (section)

==Gameplay==
[[File:Commander_Keen_Secret_of_the_Oracle_gameplay.jpg|thumb|right|Gameplay in "Secret of the Oracle". Both stunned and un-stunned enemies can be seen, as can dart traps, water droplets, and a yellow keycard gem.]]
All of the games in the ''Commander Keen'' series are side-scrolling platform video games: the majority of the game features the player-controlled Commander Keen viewed from the side while moving on a two-dimensional plane. The player can move left and right and can jump; in every episode besides ''Keen Dreams'' they can also use a [[pogo stick]] to bounce continuously and jump higher than they can normally with the correct timing. The levels are composed of platforms on which Keen can stand, and some platforms allow Keen to jump up through them from below. Beginning with episode two, "The Earth Explodes", there are also moving platforms as well as switches which extend bridges over gaps in the floor.<ref name="PCMAG1"/> ''Keen Dreams'' and later games add [[fireman's pole]]s that Keen can climb up or down, and with the exception of the 2001 ''Commander Keen'' also show the platforms viewed from slightly above so as to give a pseudo-3D effect.<ref name="SteamDreams"/> Throughout the series, once entered, the only way to exit a level is to reach the end, though for ''Keen Dreams'' and episodes four through six the player can save and return to the middle of a level, rather than only between levels like the other games. In between levels the player travels on a two-dimensional map, viewed from above; from the map the player can enter levels by approaching the entrance.<ref name="Dragon"/><ref name="ANDgameplay"/> Some levels are optional and can be bypassed, while others are secret and can only be reached by following specific procedures.<ref name="Compilation1"/>

The episodes all contain a different set of enemies in their levels, which the player must kill, stun, or avoid. These enemies are typically aliens or robots. Levels can also include hazards, such as electricity or spikes; touching a hazard or most enemies causes Keen to lose a [[Life (gaming)|life]], and the game is ended if all of Keen's lives are lost.<ref name="PCMAG1"/> ''Invasion of the Vorticons'' features a [[raygun]] that Keen can use ammo for to kill enemies;<ref name="ArchiveDesc"/> ''Keen Dreams'' exchanges this for flower power pellets that temporarily stun enemies when thrown,<ref name="ANDgameplay"/> episodes four through six use a stun gun that permanently stuns enemies,<ref name="archive4"/> and the 2001 ''Commander Keen'' has a stun gun that temporarily stuns enemies unless they are then killed with a pogo jump.<ref name="2001Manual"/> The player can also find food items throughout the levels which grant points, with an extra life awarded with enough points. There are also colored keycards which grant access to locked parts of levels, collectable items that award an extra life beginning with episode four, and items that grant an instant extra life.<ref name="ArchiveDesc"/>