Update: Got this set when the 4th of July sale was on. Love it. Some additional points not already mentioned.
There are little knobs on top of the entry doors that you turn to open and close the doors.
As shown on the box the ramp from the E-Rangers landing pad connects to the door of Plant Lab. Unfortunately the ramps are so slick that figures can't stand on them without sliding down and/or falling.
The solar panel only works with the fan, and here in Oregon it has to be in direct sunlight in the house. Outside it can be in light shade and get enough light, but not indoors. It would have been nice to have a cable to attach the fan to the battery source to run inside on dark days.
The light and the KO gun have different plugs, but there are two sets of outlets so the locations can be swapped. One cool thing that makes me very happy is that the plug for the light is the same one as in the RoboGang Lab set. So you can plug in your robot power station to the E-Rangers Plant Lab and power up your robots. And since there's the extra outlets you don't have to unplug your light. This also means that the light can be plugged into the hand cranked light unit from the lab set. I don't know if I would ever use that, but the robot station is definitely in use.
One last thing I noticed. If you look at the outside of Plant Lab and the front of the Mechanical Man you will see the answer. I'll leave it up to you to figure out the question.