After his wife and childhood dies unexpectedly from an illness, a Marine gains the ability to time travel so that he can remember all the times he spent with her.

Your logline: “Two childhood friends become lovers until one of the dies unexpectedly.”

Currently your logline only states an event…

Event: Protagonist’s lover dies. Dies of what, murder, illness, accident, suicide? Dies when, at the inciting incident, midpoint reversal? We need to know the specifics of this and most importantly HOW it changes the protagonist’s life.

• Protagonist: Not described in detail. Remember the logline formula: “an [adjective] [protagonist]”, or to put is more simply, “a [what] protagonist”.
• Goal: The protagonist has no goal. At the moment it seems that after his/her lover dies – at what’s presumably the start of the film – he/she just resorts to doing nothing.
• Antagonist: Not even hinted at. An antagonist needs to oppose the protagonist’s goal.
• Stakes: Without a goal (nor an antagonist) there’s no stakes to your story.

As it stands this a merely stated event happens which makes your logline read like a thing of the past, well before it has even started.

Please refer back to the logline formula and when writing your next logline start with this list:

• Protagonist:
• Goal:
• Antagonist:

(I’ll exclude the stakes in this list because they can be hard brainstorm for, rather they seem to come naturally when you understand the first three elements of your story.)