Adjust ball speed and sync paddle movement with game loop (GSSoC'25)

### Description
The current ball speed is too high, especially at the start of the game, which makes it difficult for the user to control the paddle and react in time. Additionally, the paddle movement is not properly synced with the ball's speed, making gameplay frustrating.

### Proposed Fix
- Reduce the initial ball velocity
- Gradually increase speed as the game progresses
- Ensure that paddle movement is smoother and responsive using `requestAnimationFrame()` or other optimization techniques

### Benefits
- More balanced and enjoyable gameplay
- Better user control and interaction
- Smoother experience for first-time players

### Tech Stack
- JavaScript (game loop logic)

I am contributing under GSSoC'25

### Request
Please assign this issue to me under GSSoC'25 so i can contribute.

labels requested-'gssoc2025' 'UI' 'BUG' 'good first issue' 'beginner-friendly'