feat: Reduce enemy respawn time frame

We can reduce the respawn time range since enemies will respawn at spots
that are offscreen, so that will add some time for them to get "on" the
map.

src/objects/Enemy.ts

@@ -93,7 +93,7 @@ export function enemy(options: Partial<EnemyCompOpt> = {}): EnemyComp {
          play('enemy_squash', { volume: getVol(DATA_SFX_VOL) });
          this.trigger(ON_SQUASH, this);
          wait(0.5, ()=>this.pos = vec2(-50));
-         wait(randi(8, 20), ()=>{
+         wait(randi(8, 15), ()=>{
             this.setAnim(vec2(0));
             this.pos = opt.pos.clone();
             this.unfreeze();