It's nice and smooth, and very polished. I like the way it plays. The bullets are nice and slow as they should be, and the nice music creates a very welcomed atmosphere. However I don't know why but the music has a lot of clicks. It may be clipping, or performance issue, but it's really distracting. Other than that it's really good :)

This is a really nice game :D I enjoyed playing it and tried it over and over again. The soundtrack is nice and the visuals are really great (because of how simple they are). 

I only had a problem with window scaling on a 4k screen :( Here is a screenshot of the browser window. 

Pretty fun game, don't remember seeing a game where you need to prevent the enemies from reaching something (which, is kind of surprising). I would've liked it if the game told me that enemies shouldn't reach the bottom though.

I thought you executed well on the idea! I was going to suggest that the game needed power-ups, but then I played  a second run and realized I just hadn't gotten any the first time round.

The power-ups are really nice. I love the way they stack, and it balances the game really well in two ways: You are you incentivized to move towards the enemies with the slow moving bullets so they're actually a threat, and as more enemies come in per wave, you also have more opportunity for power-ups which allows you to keep up.

I would suggest trying to dynamically adjust the randomness so that if you go a long time without getting any power-up drops, the probability of getting one increases, and vice-versa for when you do get them, so that you're less likely to get long streaks or droughts. 

Cool game. Really simple but polished, your focus on feedback is really appreciated.

I personally would have preferred dual-stick controls, but this was pretty solid, good job!  I really liked how it appears to start very slow but quickly gets to a lot of on-screen bullets.

I'm super into this, reminds me of oldschool geometry wars. Very clean and fun. I got to round six... I think I'll play a few more.. 
Edit: Wave 12.. this is super hard but rewarding, I love it. Cursor is kinda hard to find, a lowkey dotted line between the player and the crosshair would be nice.