Thank you for the comment!
Spoilers for Level 03 and 04:
In the third level, you have to go to the brown-orange columns in the ground and press F to make them fly to their set position. Once all are set, align the sun until you can read the words (the shadows should spell "GO UP"). If you multijump straight upwards from the very-readable "GO UP"-shadow for a little while,you should see the platform with the level finish teleport
In the fourth level, you again need to find the brown-orange columns. There are two plus the already-set gray one. The tips of the shadows will overlap at one spot in the water, that's where the platform is. If you stand right where the shadow tips overlap and call the pyramid (press C), the pyramid's shadow (specifically the upper edge/point) will sit where the final teleporter is.
PS: I'll play and rate Harvest MOO tomorrow!