Question Simple 2D animation without animator

I am trying to create a simple Animation wrapper for playing a single animation. I want to avoid using unity's animator/animator controller since the only animations in my game are explosions and impact effects so I don't need any state machines and don't want to learn it right now.

At first I created my own SpriteSheetAnimation class which didn't use any unity components, which worked but I could't figure out how to simply add a reference to a sprite with sprite mode set to 'multiple' and had to add each sprite to a List of sprites one by one.

Then I found out about unity Animation class. I dragged and dropped the sprite sheet to the scene and created a BlueExplosion.anim file. I assigned this file to a GameObject's Animation component like this.
https://drive.google.com/file/d/1ACJU5f1oqmCBcq8fOIsrIJbrpmtNWQw-/view?usp=sharing


The GameObject also has a Test component which sets the animation to legacy and should start the animation when the A key is pressed.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Test : MonoBehaviour
6. {
7.     Animation animation;
8.  
9.     void Start()
10.     {
11.         animation = GetComponent<Animation>();
12.         animation.clip.legacy = true;
13.     }
14.     void Update()
15.     {
16.         if (Input.GetKeyDown(KeyCode.A))
17.         {
18.             animation.Play(); //there is no animation visible
19.             Debug.Log(animation.isPlaying); //only 'True' is logged to the console
20.         }
21.     }
22. }
23.  

The problem is that each time I press 'A', there is no animation, only 'True' is printed to the console.
Any help would be appreciated.