While most Fire Emblem rom hacks try to upstage the mainline GBA games (most i have played have succeeded in doing so), The Last Promise successfully replicates the style of those mainline games. The story can be very generic, the characters lack depth and there are a lot of cliche characters (unlike vision quest). It lacks the story depth of hacks like Andaron Saga but because of this it feel much closer to your mainline games like Blazing Sword.

TLDR: Game is great with a lot of fun maps but it lacks character depth and it had a generic plot. Bonus credit for being the first of its kind back in the day when hack games were harder to make.