Only thing which makes human different from animals is language ...?

I quite agree. When we experience the world around us through our senses ( the examples are infinite), we are enlightened from within. Language, if understood as the capacity to produce meaning through words, is obviously a means to enrich ourselves and others. Now, add to that the capacity to communicate without words ( for example through gestures and body language, "kinesics"), and we reach the top of the communicative scale. There is a trend of though based on what they call "Emotional Intelligence" which may be very useful to your enquire. Then: Enlightment=thinking with our senses=Emotional Intelligence.

Actually, most animals have language. Just watch two dogs eye each other up. Watch cats do the same thing. Especially watch undomesticated animals in their natural habitat (or even in a strange habitat). Then compare their communications ability with each other to humans and their communications. It often looks like their communicate is far superior to that of humans, even if there seems to be no words.

What makes humans different is that we can abstract from experience, rather than confine ourselves to more or less the physical. That means we can learn from other people's experiences as well as our own personal experiences. And that we can override our instincts through thinking.

But most of all, humans have a sense of humour that can go beyond straight slapstick.

No.

We can think further than in the moment (yes, other animals can do this), but even better we can ANALYZE. That is something that any other animal has yet to accomplish. Language fits into this, but there is much more such as art and science that fits into analyzing.