Usually effects like that are achieved with paralax in the layer properties, but because in this example the layers aren't moving I guess you'll have to do it with something like a very slow speed bullet-behaviour, just like the background and foreground are moving..

It will actually only have impact on the download-size.

While playing all images will be put into memory unpacked, so a 64x64px image will take up 64x64x4 bytes no matter what format you have saved it in.

Those are the x and the y coordinate.

x = viewportleft(x)+0.5*(viewportright(x)-viewportleft(x))

y = viewporttop(x)+0.5*(viewportbottom(x)-viewporttop(x))

The fact is that it is staying in the same place at the moment..

Just like the ground that is moving left through bullet behaviour, you should make the object move left..

Your explanation is rather confusing though, the player should feel like it's running past it, but not run past it, is a bit of a contradiction, so if you could explain better what you mean by that it would be great..

A tap gesture is a quick tap, so I guess if you change that to on object touched it should work better..

or on any touch start - touch is touching object..

You are almost always working in a browser, for these are html5 games and to make them .exe's (or apk etcetera) a wrapper is used which is actually a kind of browser..

What template did you edit?

Do you want this to be a multiplayer game through network or two players at the same computer?

Both players will move if you haven't changed the controls to custom, I guess..

I have no Idea what the aimspot family is and what it's supposed to do, so futher information or a link to your capx would be appreciated..

I'd just use a group in which the elements are created and or spawned at the right positions and activate deactivate that group..

All elements would be within that group so clearity won't be lost..

That way the positions of your elements wouldn't have to be calculated every tick, for they would only exist when needed..

And to make it even more complicated

if you want exactly the center of the screen/window/viewport of the app, use viewportleft(x)+0.5*(viewportright(x)-viewportleft(x)) and viewporttop(x)+0.5*(viewportbottom(x)-viewporttop(x)) where x is the layer you'd like to spawn your object..

If you are using fullscreenmodes this is probably the only way you'll get the right position..

Seeing it works on android and Iphone:

If it's constantly returning 0 either the device doesn't support orientation or the app/game doesn't have the permission to acces it (could ofcourse have to do with the browser not having permission if you play in the browser)

I haven't fiddled with firefox OS myself, so it might be that the way to acces these informations works differently from other systems and the "bug" is inside the code to try and get acces..

There are many ways to achieve this..

one would be giving the object an intance variable and set it to the moving direction

on key right arrow pressed - object set instance variable to "right"

object compare instance variable = "right" - object : 8 directions simulate pressing right..

If you do this for all directions, you are ready to go..

I'm not sure what kind of answers you are expecting, because noone here knows your game and/or anything about how you have your events set up..

You might just be looking for a magic button within crosswalk export, but if there is I haven't found it yet..

Optimizing would consist of going over your events to see if there are many every tick events (all events without a green arrow) that don't need to be checked every tick..

see how many collisionchecks there are every second (open up the debugger for this one)

See if you are using delta time (dt) the right way to make your game framerate independant..

You could also just look at the debugger to see what is taking the most amount of processing to see where the framedrops come from..