1. It depends on which chassidus. Breslov follows the S’A and is very strict about davening on time and such (that’s reportedly why the Chofetz Chaim recommended it to his son who was getting interested in chassidus). Chabad is somewhat less strict on such things but follows the S’A HaRav. Other chassidim are sometimes less strict about such things as davening on time and tachanun.
2. They emphasize spirituality and character refinement as well as Torah study. Some sephardim and Litvish do too, but it’s not as common. See the book Jewish Spiritual Practices for diverse examples of chassidic practices.
3. Personal, spiritual connection to a particular tzaddik and his teachings are deemed very important for one’s avodas Hashem.
4. Joy, love of Hashem and one’s fellow Jew, and belief in all-encompassing divine providence are emphasized. Prayer in one’s own words and various meditative practices are employed.
5. Chassidic teachings and spirituality are essentially contained in books and the personal teachings of Rebbes, and can be practiced by any Orthodox Jew, regardless of appearance or affiliation. So some sephardim, Yeshivish and MO Jews draw on chassidic teachings to a large degree and yet retain their traditional appearance and affiliation.
6. Chassidim were more fervent fighters against haskalah (as mentioned by the Chofetz Chaim) and were the main ones brave enough to risk their lives by spreading Yiddishkeit in the Soviet Union (especially Chabad and also Breslov).