Ivanna

The plot works as it is. It's simple but the movie executions made up for its plot. It does waste some time to explore the "mystery" (Though from my personal experience, it's pretty predictable).

Now, the eerie/creepy moment at the start of the movie is the best part of the movie for me. Watching a headless body walks in the background with unaware characters really sells it. The atmosphere support these scenes.

The problem came with the slasher part of the movie. Without spoiling much, the movie only uses one kind of execution. Usually, one of the fun part of a slasher movie is watching how the killer creatively execute his/her victim. In Ivanna there is only one method, and it start gets boring aftering watching it done for the third time.

Overall, it's entertaining enough for me, for an Indonesian horror movie, it does a decent job.