If you use blue or white LEDs they are much brighter but you'll have to use 3V cells because of the higher forward voltage.

add solar panel, and meybe real forever https://www.youtube.com/watch?v=KOZY5DXpZpY system . moving=electricity power

Great Idea! I actually did that with a version of this circuit a year or so ago. That circuit used a solar cell from a calculator to charge supercapacitors during the day. It would last about 3 days after being charged in direct sunlight for ~30 minutes. Unfortunately I was never able to make the circuit operate by just using the solar panels to power the circuit directly using indoors ambient light, so I'll definitely be trying that next!

Currently working on increasing the brightness of each flash of the LED without significantly increasing average current draw