There are lights that appear at happy moments and a ghost girl trying to get to older sister to find her own happiness.
However, for someone to fully appreciate Clannad they'd have to have played the visual novel. There are extras called the Kyou and Tomyo arch and the last episode of the series acted as a sort of reset. It's better to think of it as "okay, so that's one ending what would've happened if the people had lived? Or if he chosen this girl?" Now you get to peek into some of the other possibilities. I was sort of disappointed that my favorite character didn't get an arch with Tomoya (an Tomoya x Kotomi story).
The anime is funny and sometimes just the characters actions were enough to make you laugh. Some of the characters, such as Fuko, were just too cute but the overly cute moments didn't last long and then it was just the right amount of sweet to counteract the more dramatic parts of the show, especially with Kotomi and Ushio. There is something in this anime for everyone almost.
The movie is a bit different from the anime but covers all the main plot points in a shorter amount of time is worth the watch. You won't feel as connected to the characters if you don't watch the anime first but it's just as beautiful none the less. I actually liked the "other world" people's betrayal better in the movie as it makes a little more sense than the two people in the movie but you're opinions may vary.
The animation and music is absolutely stunning. I'd suggest watching it with subs though as the dub voices just don't match the characters. At first the tune to "the big dango family" is just kind of meh but by the time you finish the series you'll find that cute little tune stuck in your head.
