I've completed this game (also wrote an article on it on TV Tropes: https://tvtropes.org/pmwiki/pmwiki.php/VideoGame/Spectacle) and I'd say it's amazing, feels just like the NES ports of MacVentures without the hardware limitations affecting the graphics/sound/gameplay and with more modern design principles.
Kinda wish there were some extra lines for stupid actions like "TAKE SELF", though, just for laughs. Also kinda disappointed there's only one savefile, but I get it was done to not make the challenges too easy. I will play Infested as well. It'd be interesting to see how a third GrahfVenture could top this one someday.