typedef struct
{
    CBitmap* sprite;

    int speed;

    int maxHealth;
    int flags;
    int projectileDamage;
    int contactDamage;
} CEnemyClass;

typedef struct
{
    CEnemyClass* _class;

    int health;
    int nextAttack;
    int x, y;
} CEnemy;

        // Asteroid
    enemyClasses[0].sprite = &sprEnemy1;
    enemyClasses[0].flags = ENEMY_FLAG_NONE;
    enemyClasses[0].maxHealth = 45;
    enemyClasses[0].contactDamage = 15;
    enemyClasses[0].speed = 2;

    // Regular unit
    enemyClasses[1].sprite = 0;
    enemyClasses[1].flags = ENEMY_FLAG_CAN_SHOOT;
    enemyClasses[1].contactDamage = 20;
    enemyClasses[1].projectileDamage = 20;

    // ZigZag shooter
    enemyClasses[2].sprite = 0;
    enemyClasses[2].flags = ENEMY_FLAG_CAN_SHOOT | ENEMY_FLAG_ZIG_ZAG_MOVEMENT;
    enemyClasses[2].contactDamage = 20;
    enemyClasses[2].projectileDamage = 10;