Well if GM does use activex to play in browser then after IE8 it may not work anyway (Microsoft may be dropping IE after 8 for a newer base).
->http://www.osnews.com/story/21120/Microsoft_s_Next_Browser_To_Be_Based_on_Gazelle_
Just thought i would mention that for future use i think Construct is better since it is open source and actively developed with an ever growing decent community.