Here are a couple of the other ATtiny projects I've worked on. Only now just writing them up. They are both pretty simple.
The first was an Iron Man style "ARC reactor" (the circle light in his chest) that I made to go with my son's (shop bought) Iron Man costume. It was just three blue LEDs covered in translucent Fimo, that light up in sequence, stay lit for a few seconds, then shut off in sequence.
Here's a video of it in action.
The whole thing is powered by a watch battery and activates when a button is pressed, then goes back into a power saving sleep mode after running the animation, till the button is pressed. The code is pretty similar to the robot santa code and is over here on github.
The lighthouse involved a fair bit more craft work, but was even simpler from an electronics point of view (only a single LED). I first made a mold using a hexagonal jam jar as a base, then cast the "light" part out of resin with a large white LED embedded inside:
I then attached this to a re-usable plastic coffee cup (with branding sanded off) and added a fair bit of milliput to create a balcony etc.
Next I painted the whole thing with white and then red spray paint (masking the paint to make stripes).
I then mounted that on top of a piece of wood and added some chunky buttons (one for power, one to trigger the light).
Here's a video of the light turning on and off:
The code for the lighthouse is over here on github.
This post is a bit light on details, but mostly these are variations on what I already did with the robot santa (minus the speaker). Hopefully shouldn't be too hard to work out what's been done here.