Thanks mostly to all the attention that the game got outside the calculator community, but also the many fans that the game got during its two and half a years development stages, Portal Prelude for the TI-83 Plus has managed to reach 8000 downloads only one week after being released! On top of that, the day before this achievement, the game surpassed gbc4nspire (http://www.omnimaga.org/index.php?action=downloads;sa=view;down=484) (online since March 2010) as the most downloaded (http://www.omnimaga.org/index.php?action=stats) file in Omnimaga archives (http://www.omnimaga.org/index.php?action=downloads) overall.
Portal Prelude: 8328
gbc4Nspire v0.9: 6832
NspireEmu (outdated): 4771
Ndless (ticalc mirror): 3360
Ndless (v2.0): 2434
TI-Boy SE: 2036
Ncubate: 970
Reuben Quest: Ev Awakening: 879
Pacman Nspire: 793
BBC Tetris: 701
If we also include programs that are only released on the forums as attachments, it even surpasses nDoom (http://ourl.ca/9206), which got a lot of attention outside the calculator world back in 2011. nDoom isn't in Omnimaga archives, but the attachment file has 2119 downloads (2999 with the source). In that case, only Axe Parser (which was used to make Portal prelude) appears to have gotten more downloads in total (10768 for all versions (http://ourl.ca/4060)). All sites included, the most ever downloaded Omnimaga staff release is Zelda: Dark Link Quest, with 48136 downloads during its first stay (http://xlib.mtv-music-generator.com/ticalcacct.gif) on ticalc.org.
It is rare for an Omnimaga program to get that many downloads in such a short period of time. The previous record for weekly download stats was xLIB xLIB Revolution in October 2005, peaking at 2800 downloads (http://xlib.mtv-music-generator.com/xxrstats.gif) per week (ranked #1) on ticalc.org. Both Portal and XXR made Engadget and ticalc.org front page, as well as many other popular sites after their respective releases.
Congrats to Builderboy!