(borrowed your cover, gagaman, hope you don't mind :P)
Looks like Counter-Strike DC has finally reached its final stage of development. Here's what the guys behind it have to say:
This project has finally reached its final v.1.0 release.
You will find hours of Counter-Strike gameplay, now on Sega Dreamast.
This final release is now very stable, and is fully playable with a standard controller.
And for the record, this project was intended from the begining to be
a great single-player experience. So to answer with certainty,
online/multiplayer will never be possible on Dreamcast.
Standard half-life dc codes work from the menu, for example:
"Otis Loves Dreamcast" --> God mode
"Dreamcast Gives Firepower" --> Infinate ammo
Also, huge credit goes to original authors of the content that has
been borrowed with or without permission for this release.
Looks good to me. You can download it here, and here's a gameplay video: