No bugs! Here are some nits you could consider for improvements. At a very basic level, I usually start by working on the core game mechanic -- in your case, that's (a) flying and (b) shooting down birds.
- You could make flying more dynamic. For example, the drone could wobble left and right based on how quickly or slowly you drag the drone to the left and right. There could also be a slight lag as the drone catches up to your cursor. For what it's worth, the buzzing of a drone is really annoying, so granted, you might not add a realistic sound effect here haha.
- You could also making shooting more satisfying. Have the bird thrown backwards when it's hit, maybe shoot some sparkles into the air, or have the bird vaporize. You could also add a little +1, along with some sound effects to achieve this. The drone itself could animate when it's shooting as well. For example, the drone could scale up and down as if it's "spitting out" the laser.
Once the core game mechanic is more fun, then I think the next most important goal is setting up a clear challenge. You've already got a clear goal (survive until time runs out) -- so it's just a matter of adding more challenge. For example, you might force the player to use the laser with a wall of birds that can't possibly be passed. Or, you might penalize the player (time increases) for every bird that passes you.