I liked that the targets were various colours and stood out in the environment. I liked it when you shot them they would suck up anything around them as well.
I didn't enjoy that there was a set time and I just had to get as many as possible in x time, rather than being able to get something that would extend my run. The sound of shooting the gun was a nice touch. Would have also liked that there was something to tell me about my reload even if it was a number or something rather than spam clicking waiting for the next time to shoot to be done.
I also found myself looking around the environment but disappointing to the time wall that I could go look around the nice looking scene you had. I could explore in tutorial but was bogged down with control ui that I couldn't toggle off.
It looks like you put a lot of work into this and you should be proud of what you made, it is pretty cool.