You can do that using blendmodes, see the example in the new projects option menu.

I guess I would:

Set the physics collisions to bounding box.

Try setting friction to a higher number.

It should work. place the button in a reglar html page ... view it and click ..

that page you get from paypal .. to actually donate money to your email/account, copy the link and have the button you design in your app open that url in a new window :)

use the custom movement, on overlap push out solid opposite angle. maybe you should set the speed also, but it should work.

Check the asteroids example in the arcade

Sounds like you want to recreate the spaceship movement from asteroids. Instead of reinventing the wheel, maybe you should take a look at this tutorial:

Asteroids tutorial

translate number between ranges. so translate from health number to opacity.

You just have to add a for each valkyre to the last event. You are not picking a specific instance in your event so it affects all instances.

the formula I posted works if you want to find a number.

let's say you have numbers from 0 to 100 and you have to translate it to numbers from 25 to 250. in-min is 0 out-min is 25, in-max is 100 out-max is 250, so if you've got input 10 output would be 37.5

That's probably about the same effect as this formula to calculate from one range of numbers to another. (which I didn't think up myself, but use a lot now)

//(x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min //

This is not a Construct2 question, is it?

I guess you'd have to use PHP on a server and make the ajax call to that. I don't know anything about PHP, but I know it should be able to send a file when getting the right call. So yes you could use Ajax to make the call from construct2, but you'd need to know PHP to do anything useful with that call.

change your orignal event (jump button) is down to on (jump button) pressed and keep the jump button is down in the on landed event.

How were you hoping to make sprites more red, without adding sprites or animations or effects?

Effects per sprite would probably be a bigger strain on your system than just adding 1 completely red sprite.

Animations would mean adding a lot more sprites than that.

Also doing it the way I explained you wouldn't have to use WebGL.

If you'd rather use webgl per sprite you could use the tint effect or the hsl effect (maybe there are others that would even suit you better), but it would probably be a lot more intensive for your processor.