These features are optional, but the cheapest option is $50, much cheaper than C2.
—: Well, you're comparing stuff which aren't comparable there.
C2 aims at HTML5 export by default, and this has been their selling point and aim from the get go.
GM allows HTML5 export in their Professional edition (that costs 89.99 $) with an add of 89.99$ so a total of 179,98 $ for HTML5 export.
This is more than a personal C2 license and less than a Business license. (GM prices in the tab of this page).
Talking about the 50$ GM version, still according to their tab it only allows to export to exe, which is not the point of C2 originally.
For the price of a C2 license you get access to EXE AND mobile exports (even if you label those as crippled).
To get the same in GM, you have to add 179.99$ for iOs and another 179.99$ for android. By the look of the array I linked earlier, to get full mobile and EXE export in GM, as I understand, you need to buy it for 539.94 $ which is more than a C2 Business License.
Gamemaker also has a much bigger community, but you don't get such direct access to the devs so tie there.
I don't think it's as much the size o the community that matters than the amount of help it provides. On that point, I don't think C2 has to blemish at all.
Also from what I've seen in numerous posts on this forum (I never used or was part of their community) our community is friendlier and more helpful.
You can see the tutorials section filled with users provided content, as well as the forums which tend to answer and provide help to who's seeking some.
PLUS you get the insane presence of C2's devs and the opportunity to have discussions such as this one which won't get censored or closed.
Tie it if you want, I know I'm biased but to me C2's community/forums/site wins it big time.
Unity provides fully functional support for all platforms, for free. If your interested in mobile, 200$ with game maker or gideros or something for functionality over $120 for a currently crippled system is much better.
Like above, look again what you're comparing.
Unity on desktop is a plugin you need to download first.
I personally have not installed it, but still I can play any HTML5 games including games made with C2.
It means the potential target for your HTML5 games on desktop is already wider than for unity's games.
For the mobile, there's already have been so much improvement since the experimental mobile export that in a near future, mobile export will work as good as native.
I can already decently play my games in LAN preview on iPad2 a bit less decently in android, but it has updates and improvements also coming (and I haven't yet tried cocoonLauncher, slowly getting there :D).
Again, your estimate of GM's price is wrong. See earlier.
Also, C2 offers "Team features" by its format, you can put your folders in a SVN type of server and use it as a team even in the free version.
Another feature that GM prices for at least 89.99.
It's fine to play the devil's advocate but I think you should play with fair arguments <img src="smileys/smiley1.gif" border="0" align="middle">