Thanks for feedback, glad you found the shadow mechanic cool! I agree it's definitely a little too challenging to initially wrap your head around how everything works, and more tutorial levels would have been good.
There's some white squares in the first level after the tutorial in areas where the "intended solution" puts green lights, but I've seen 3 completely distinct other solutions to that level. Though first, you have to of course move the two lights away from the gap so the entire gap is full of shadow.
Thanks for playing!