Unfortunately there are no legal grounds.
Firstly, software is exempt from the laws that surround warranty and guarantee. So we have no claim against the bug in the core game
According to the definition released by the National Endowment of Arts this year:
Projects may include high profile multi-part or single television and radio programs (documentaries and dramatic narratives); media created for theatrical release; performance programs; artistic segments for use within an existing series; multi-part webisodes; installations; and interactive games. Short films, five minutes and under, will be considered in packages of three or more.
source: http://www.forbes.com/sites/insertcoin/2011/05/12/video-games-now-legally-considered-an-art-form-in-the-us/
I would think the above would start to provide some legal recourse to consumers as it opens doors for other rational questions. Can independent game developers seek government funding -- grants ( suggestion made in the above linked article)? And maybe it is time to advocate for a change in laws covering warranty and guarantee. The flip side is probably not desirable. Should game companies become responsible for releasing "bad" products, some companies may opt to get out of the game development business all together for fear of class action lawsuits popping up everywhere. Thus, lawmakers would have to define what constitutes a "legal" product and can be considered protected against frivolous lawsuits. I'm not talking about copyright protection. That is a different area. I'm talking about - for lack of better terms -- a lemon law for "interactive games". There are a whole bunch of questions to be asked and answered in a sensible fashion.
When is an interactive game considered a "lemon"?
How should laws governing false advertisemant be applied regarding advertised features left out due to business decisions yet never publicly retracted?
Who is ultimately responsible for the product -- retailer, publisher, or developer (liability)?
What kind of clocks should be established for patches that prevent interactive games slipping into a "lemon" status?
What about product recalls? The problem with this question is software is a non-physical product. It's not real -- tangible -- and therefore poses no "physical" threat to consumers. And no, don't bring up epilepsy. If that is an issue, you shouldn't even be using the computer -- ie: a strobing light in the form of screen refresh rate.
I'm sure you could come up with your own questions. I'm just shooting from the hip here and I'm not a lawyer.