gamemake is weak and slow
I tried making a bezier curve generator with it, and if you try to make gamemaker do more than a few hundred commands in a frame, it starts to slow down, you can even make the command do nothing, like a null command, and it still slows down.
construct lets you do a few thousand things per tick before it's interpreter causes a bottleneck,
Last time I heard, Python in Construct is very weak/limited and need's alot of improvement's.
as far as python goes, python with construct makes gml look like a toy,
python is a full language, every bit as powerful and complex as a real compiled language like C++, aside from speed that is, though it is still at least an order of magnitude faster than gml, but even faster is...
Idk, the main thing I liked about GM was how tight it was with GML. It just worked. (And the syntax was close to C based languages, the learning curve is next to nothing)
aside from python, which is insanely c-like
you can make plugins for construct fairly easily using c++ ,
everything you do in construct is done with a plugin, from loading an image into a sprite, to applying a platform behavior, to playing a sound, to opening a file dialogue. they are as powerful and fast as the c++ that spawns them. the possibilities are endless.
I used gamemaker for a while, I even bought it. it's a neat little tool for what it's worth, but it's very limited. With construct, a dedicated user could create World of Goo, or Braid, Plants vs Zombies, or Aquaria.
with the speed, and the pixel shaders, it's definitely possible to create the next big thing in 2D.
one last thought, people keep saying rapid prototyping without really explaining what they mean exactly. I'll give you a quick example or two. somebody asked if it was possible to create a 2d version of katamari damacy, and upon reading it I was able to create a playable, albeit simple graphiced, example of a 2d katamari damacy prototype in 5 or 10 minutes. I haven't frequented the help forums in some time, but it was quite common for someone to ask a question starting with "is it possible to..." followed by something that has no built in object or behavior in construct, and the response within a few minutes be an actual working example of what they were asking for. it sounds too good to be true, but I mean it. The fact that there is even a such thing as a 1 hour game competition thread speaks volumes