Definitely a fun game to play, I enjoyed it.
Love the basic premise of time being everything and the upgrades costing time, makes decision making a lot more interesting. And the upgrades that are there are also fairly interesting and do have somewhat synergy.
So based off of that the gameplay does definitely feel nice. There are a couple of issues, mainly being that at times player and bullets could both travel at the same pace with each other - which isn't too much of a complaint to be honest.
The enemy hitboxes are a bit weird, it feels like I should hit, but I don't.
I also would have preferred a Cursor and Mouse button to shoot but this isn't too bad once I got the hang of it.
The shop is still a bit weird for me, I have to minimize full screen to see it better, which could just be a local issue but I am not sure.
The art style is nice enough but could be improved upon same with the sound design
Apart from that, I did enjoy the game. Great work!