It's a good game and a good idea, well done!

The only thing I didn't like is the fact that movement is unnecessary: since enemies spawn from only one direction, you can go the other direction and shoot them peacefully, you can fix that by adding collectables objects (coins), or letting enemies spawn from all directions.

Anyway, good job! And please check out my 2 submissions:  Speedrun Unlocked ! and Escape the Bug.

I think you could definitely crank up the difficulty, and with the enemies coming from 1 side it became kind off repetative, i did however really like the tank controls!! nice little game!

A couple of issues that would make the game a much better experience:

1 - Make the tank more distinctive in its direction, the little green dot was easy to miss.

2 - Remove the instructions when the game starts

3 - Add WASD also to controls had to play with arms crossed because of the location of my arrow keys.

4 - Does a player really need to know the time to a 1000th of a sec?

But I enjoyed the game still.