# Commander Keen 1: Marooned on Mars — shareware episode

This package contains the freely-distributable **shareware episode** of
Commander Keen: Invasion of the Vorticons — Episode One, "Marooned on Mars"
(id Software / Apogee Software, 1990), original `KEEN1.EXE` and .CK1 data
files dated 1990-01-23.

Episode One was released as shareware under Apogee's distribution model,
which explicitly permitted unmodified copies to be shared freely — that was
the whole marketing mechanism of the trilogy.

Source: DOS Games Archive — https://www.dosgamesarchive.com/download/commander-keen-invasion-of-the-vorticons
(pre-installed "Keen Box" package; retrieved 2026-07-27).

Episodes 2 and 3 remain commercial — the Commander Keen collection is sold on
Steam. Modern additions from the source package (icons, FAQs, wrappers) were
removed; only original 1990 game files plus a DOSBox configuration are
included.

ExeBrowser is not affiliated with id Software or Apogee/3D Realms.