Lara Croft and the Guardian of Light will launch for Xbox Live Arcade without its online component, which will follow in a patch at the same time as the PC and PlayStation Network versions in September.
Square Enix also said that it will release five downloadable content packs for the game between October and December, expanding the range of puzzles and even playable characters.
The Guardian of Light is due out on 18th August for XBLA in a one-month timed exclusive deal and will launch with two-player offline co-operative play only.
Then on 28th September Square Enix will deliver the PC and PSN versions, including two-player online play. The XBLA version will be patched on the same day, also receiving leaderboards and voice chat.
Of the five DLC packs, the first three are expansions offering "new puzzle, exploration and combat experiences in the game and new areas to explore", while the last two introduce a pair of "well-known videogame characters" in playable form.
Global brand director Karl Stewart told Joystiq that the decision to release the XBLA version in offline-only form was based on delivering quality.
"If we had launched with online co-op, we wouldn't feel comfortable that it was the best possible experience for the player," he said.
Check out our Lara Croft and the Guardian of Light hands-on preview elsewhere on Eurogamer to find out what Larry's up to in her first isometric downloadable adventure, or read our recent Crystal Dynamics interview for more on Lara's history, sex in games and hints about the next full Tomb Raider.
Lara Croft and the Guardian of Light will cost 1200 Microsoft Points (£10.20 / 14.40) on XBLA and $14.99 on both PlayStation Network and PC (Steam).