Shrinking enemies to change their threat level by altering their size and subsequentially their projectile size is a very good application of the theme. Overall a great game, though I find it lacks interaction with the world/level. The game seems to predominantly operate between player and hostile NPC.
Discoverable powerups and destructible objects of the environment would be welcome additions to the gameplay. Given more time and effort, a system of metaprogression could be implemented where players spend resources to upgrade their stats permanently, for example. Perhaps using currency gained from traversing the map and destroying chests.