Your comments

Try connecting your intensity value to opacity, without changing its blending mode
Does Unity's default shaders support this?
Because I can't find why this wouldn't work unless it's a Unity bug
Odd - it should work. I'll have to look into this. Have you tried modifying the blending settings?
That's a pretty good idea, yeah. We'll see if it makes it in :)
I'm not sure how you would do that, try asking in the forums. This place is not for "How do I" questions, so, I'm closing this :)
Hey!
Thanks for the example :)
This is something I haven't had time to look into yet, but it may come in the future, along with 2D shaders!
Seems like it's a bug in the asset store system. I believe this might be solved if you try these steps:
http://acegikmo.com/shaderforge/faq/?Q=erroronnewversion#erroronnewversion
Not really, no, that's usually done using a light cookie on spot lights or projectors
Not really! Although since you've already bought SF, I presume you've already paid for it anyhow :)
Thanks though!

I know this works, I've had it confirmed in Unity 5 PE, so it has to be some other error on your end, I'm afraid.
  • Make sure the slider is set to anything other than 0
  • Make sure you're actually looking through that very camera after pressing play. It may still look wrong in the scene view.
  • Make sure the shader doesn't write depth (under the blending settings)