It's just fine, but if the ball were smaller and had a sensor, it would be excellent. I had bought one like this from China and it was amazing and cheaper, of course, so I will probably have to get it again.

It goes with force and hits doors, chairs, etc. and makes a loud noise. It bangs completely uncontrollably wherever it finds and it's annoying. At least, instead of smooth, hard plastic, it should have a soft cover, e.g. made of EVA or fabric. Now it's abandoned in the closet. I regret spending the 20€.

The cat plays a little (a few minutes) every time I put it on. It gets bored immediately because it sticks to the carpets and makes a lot of noise on the floor.

It's fun, my dog doesn't really chase it but it keeps his attention. The biggest problem is that the plastic makes a lot of noise when it falls on things.

My cat is thrilled with this toy and plays with it constantly. It is very durable and its batteries last for many days. It also activates with motion, so it can play with it whenever it wants without wasting batteries unnecessarily.

It's not bad, but it's not perfect either.
Personally, what I noticed with my cats is that the hard plastic it's made of makes a lot of noise on the tiles, causing some cats to be afraid of it.
The other downside is that due to the choice of this smooth plastic, it doesn't move easily on carpets (it even sticks).
In terms of durability, it has been hit several times against strong walls during playtime and it seems to withstand it.
The mechanism is in a well-protected position. The batteries last for months and I always keep it on hold mode so that the cats activate it when they move it.
I tied feathers to the string because the bell reduces the cat's interest in approaching it. I would only recommend it for very active cats that are not generally fearful, otherwise they won't approach it because of the sound.
I would say 3.5 out of 5. If they make it with a different type of softer plastic, it would be perfect!