It's such complete and utter junk that, eight hours after unpacking it, I've put it back in its box ready for the return. The major issues are:
There is no battery indicator of any kind. So you can't tell when or if it's fully charged and you certainly don't get any information on the charging time in the "handbook".
There are three motors, one for each main rotor and one for the tail rotor. Trouble is: the two flight motors don't behave the same as the battery runs down, which (obviously) happens very quickly. So one moment, you're managing to keep the thing in the air and the next, it's starting to go in circles. And when you use the tail rotor to control the pitch, it uses so much power that the helicopter can hardly stay in the air... when the battery is full. When it isn't, you're lucky to get it off the ground in the first place.
and finally: A small plastic cogwheel that rotates a bigger one on the drive shaft for the upper rotor is not properly fixed to its own drive shaft. So it simply won't stop slipping until it loses contact with the bigger wheel. Which means that the upper rotor will suddenly lose all power in the middle of flight. And then the whole thing will plummet to the ground in uncontrollable circles from whichever altitude you've managed to get it to, depending of course on your luck with the battery and the controls.
Of course, I didn't expect much for 25 Euros, but neither did I know that you can make something this atrociously bad. I literally hadn't thought it possible.