Seriously, I recommend everyone do this. Take screenshots of your work so you can look back and see how your project has grown. I regret that I didn't take more screens during development, as it's always fun to reminisce the various stages of development, good and bad.
This is an excellent point! It really helps to be able to look back and remind yourself of all the ways your game has developed!
here's a few from the earliest playable build of Assault Android Cactus I can find (and current version)
The funny thing is the early screenshots are from maybe a week or two after I first downloaded Unity. Getting a character running around and shooting was really straight forwards! But it's taken from then until now to understand and refine the gameplay. (and the graphics have gotten a little better along the way)
This is the latest level I've been working on! It uses a series of squares that relocate themselves to be under the players feet (with a slight offset based on the players current velocity) and the pattern is driven by a texture that can change over time. Since blocks can't switch if an enemy (or player, or powerup) is currently on them, the enemies sort of drag the level into elongated shapes, so if you try to back-pedal too much you run out of level (but you can get more by shooting enemies and letting the level spring back... it's... sort of hard to describe how it plays)