Corwim: Just stumbled across this topic, I LOVE what you're doing here Fever_Discordia, bookmarked! And +1 for you! Really hope a lot of these games will one day see a GOG release!
I have this weird (lol) obsession with everything that has to do with Sierra games (I'm also collecting physical releases of all their games :-) ), and think there might be a few missing on the list here, under the Activision heading. I'm new to this whole, at times, confusing rights issues, so I apologise before hand if some of these do not belong in this topic, for any of the reasons you have stated in your first message (unsigned publisher/licensed/other games in the series already on GOG, ... ), or were already mentioned before.
Ok, here we go: :-)
<span class="bold">Lighthouse: The Dark Being</span>:
Published by Sierra in 1996. I remember reviews of this game back in the day mentioned Coktel as the developer of this game, but I can find no trace of that on the actual box of the game, nor on Mobygames. As far as I can tell, this was on original IP and wasn't part of a series.
<span class="bold">Air Bucks</span> and
<span class="bold">Space Bucks</span>:
Air Bucks was developed and released by Impressions in 1992. An updated version of the game was then released as
v1.2 in the Sierra Originals budget line a year later after Sierra took over Impressions (so I assume the rights to the game should now be in the hands of Activision). Space Bucks was developed by Impressions and published by Sierra in 1996. Both games are business simulation games, so while Space Bucks is not an 'official' sequel, they do belong to the same 'Bucks' series.
<span class="bold">Robert E. Lee: Civil War General</span> and
<span class="bold">Grant-Lee-Sherman: Civil War 2: Generals</span>:
Civil War Generals series, also developed by Impressions and both games were published by Sierra (first one in 1996, the second one in 1997). Both games were TBS war games, and looks like they were an original Impressions IP, and not part of their other series.
<span class="bold">Fast Attack</span> A submarine simulation game, developed by Software Sorcery (no idea who they are lol, but apparently they also developed Conqueror AD 1086, which is on the list, for Sierra) and published by Sierra in 1996. Again, looks like this was an original IP and not part of another series (eg it's not part of Dynamix's Aces series).
And then there's one more Microprose adventure game that might belong on this list as well. I don't know which IPs all transferred to Tommo (in fact, not sure which Micrprose IP they got, but judging by recent additions to GOG, it was quite a lot :-) ). And that game is
<span class="bold">Return of the Phantom</span>. According to Mobygames, it was developed by MPS Labs which is also linked to Dragonsphere and Rex Nebular, two Microprose adventures that are already on GOG! :-) Return of the Phantom dates from 1993. It does seem that it was loosely based on the 'Phantom of the Opera' novel from 1909, but I think that one's too old to cause any licensing issues.
Again, I apologise if any of these don't belong in this topic! :-) Oh, and I don't know about the quality of all of these, but like you said in an earlier post, the list does not judge. :-D
I added all those Sierra-Activision ones as well as "Edward Grabowski's The Blue & The Gray" which got bundled with the 2 Civil War Generals games at one point but seems to be its own thing
With the Tonmo games, we're in the strange position of having a legal document - here:
Listing exactly what they bought from the Atari estate - so far all the Tommo Atari releases have been from this list...
Oh BTW, I added 'Killer Is Dead' under Deep Silver recently too - damn good to see that one come to PC, if not yet to GOG!