HOWEVER, be prepared to deal with HTML5 which is a load of rubbish, since Scirra team refuses to use anything else for the main framework.
Meaning you're going to be limited to the point of not even bothering with mobile devices...
In two mobile games I'm making, on an iPhone 4S/ipad 3 I get 50-60 fps in battles and a smooth 60 fps out of battles in one game, and generally 50-60 fps in another as well (can dip down to 37 if I throw a lot of stuff at the player at the same time) and I might be able to optimize them more.
and good luck with file io stuff because it takes the simplest stuff like writing to a file and turns it into a confusing mess.
Scirra recently added file io to node webkit, making it a breeze on desktops when exporting to exe.
I'm still using Clickteam Multimedia Fusion 2 because it's by far the best tool out there that actually can export natively to an EXE.
The only benefits I've found of a native exe anymore over C2's use of node webkit is some increased code execution speed that 99% of games don't need, and a 'true' fullscreen mode (node webkit uses a fullscren borderless window) which can improve fullscreen rendering performance a little bit on XP and vista if aero is disabled (as XP and vista with aero disabled use a window manager that is not hardware accelerated, degrading performance a bit - vista with aero on and windows 7 and up have a hardware accelerated window manager, so true fullscreen makes no difference).
While it's true there's still some kinks to be ironed out on node webkit, progress is steady and in most cases it works great already.