The subtitles not matching to the audio was a bit distracting. Be more attentive about that in future animations. Additionally, placing them in odd locations throughout the frame doesn't help - just keep them at the bottom of the screen like normal subtitles.
The audio itself was also a bit too inconsistent for my liking both in quality and tone. Some of the effects were a bit TOO goofy and ruined the mood. The sonar scan and the laughing skeleton were the bigger distractions. The background music was nicely leveled and suitable for this small animation.
Another thing that brought this down were the colors. Either they were too dull or they were too bright. Try looking into color theory and paying attention to how cartoons, anime, etc. use color to their advantage in setting tone or directing a viewer's attention. (It also seems like you forgot to color a wide-angle shot).
What does make me like this animation from most newcomer submissions is that there is some creativity put into it, such as the creepy baby growing three heads and then into a demonic monster who eats the priest. I especially liked how one head ate him while another spit out his blood. That was neat.
But, yeah, the lack of good coloring and the sound effects bring this down for me, keep at it though, there was some potential I saw here.