Complete the following achievements to unlock Microsoft Gamerscore points.

Achievement	How to unlock	Points
Favorite tower	1 tower improved completely.	100
In full sail!	Reset each wave timer.	200
Invulnerable	Episode levels passed with 3 stars.	100
Last chance	Level passed with 1 hp.	100
Long John Silver	Only one ship attacked the outpost.	100
Magic storm	200 spells cast.	100
One thousand demons	1000 ships sunk.	100
Sea dog	Level completed in fast mode.	100
Strike me down!	Level failed 3 times in a row.	100
Top marks	Pass the level with 5 towers.	100
Volley from all the guns!	All gun platforms are occupied.	200
Warlock	1 spell improved to max.	100