This probably isn't as interesting to anyone else as it is to me, but I figured I'd share anyway just in case.
It turns out most of the graphics in this "alpha" screenshot are present in the final game, although slightly modified in places, so I tried my best to recreate it. The leaves are used in a few places. I swiped them from Denadoro Mountain and altered the palette. The sky/distant mountains were taken from Denadoro as well, but I tweaked the palette a little and altered some of the mountain peaks to match the screenshot. The ground tiles are from Death Peak, and they use the same palette as Death Peak's ground tiles in the final.
The Heckran sprite in the screenshot is considerably different from the final, but I didn't want to mess with it so I just pasted in the final one. Same goes for the flames.
I
did modify all three of the character sprites.
Chrono's sprite seems to be almost identical to the final, except that I had to move the blade of his sword a little.
Frog's sprite is a little different from the final. His feet don't stick out quite as much, and his tongue isn't as big.
Marle's sprite I had to cobble together from two different poses. That exact pose doesn't seem to exist in the finished game. I also changed her hand so that she has a finger extended.
The menu background is basically just the default from the final without the HDMA gradient and with a custom blue palette. I did add some highlighting on the right edge tiles though. Looking at it again now I think the right edge tiles might have just been mirrors of the left edge at this point in development, which would mean mine are slightly wrong.
A few of the Japanese text characters appeared different as well, so I modified them a little. Specifically ざ ン パ ル and ス.