Getting two (or, one and a half) outputs from a single pin
Honest truth: What you're trying to do is easier implemented just by using a microcontroller with enough pins. It's probably even cheaper than an Attiny85. Who knows.

But: If you really must, you can do various things to get more output out of a single line:


Buy an IO expander that uses the 1-Wire (pseudo)standard, and implement a 1-Wire transmitter on the Attiny
an UART device might do as well, but I don't know of any single-wire-UART-to-IO adapters that aren't actually just another programmed microcontroller
Implement a DAC, followed by an ADC


DAC by PWM'ing your output,
feeding the PWM into an RC low pass filter, yielding a "smooth" variable voltage
buy a cheap parallel output ADC, or
implement your own parallel output ADC with Zener diodes