1. Does the game feel fun to play
Yes. The ship controls well. It's snappy and responsive. The sounds and flashing of the enemies gives good feedback for hitting them.
2. What did you like about the game
I thought it was a good design choice to have the ! symbols to show where enemies were about to spawn. Also, there does seem to be a good amount of enemy types so far. Including the scoreboard was a good decision to encourage repeat play. I managed to get a score of 490.
3. What did you dislike about the game
I think the main thing the game is lacking is options in how to approach enemies, limiting player agency. Once you get overwhelmed with enemies, there is little you can do to combat them. Maybe you could set a limited number of mines? Some kind of dash or dodge mechanic? Power-ups to upgrade firing rate? Something to give the player more tools and decisions on how to tackle enemies. Once overwhelmed, the player has practically no recovery options.
4. Is the game too hard or too easy
I do think the game gets too hard too quickly, especially when the bombs and slow enemies that show up in the first 30 seconds of the game. I think the spawn rate needs to be adjusted so the player doesn't get overwhelmed so quickly with enemies. I would suggest a more gradual increase in difficulty. This would give the player a good feel for the game first before they are really tested.
5. bugs
Only bug I noticed is that sometimes, after getting a game over and restarting the game, the ship would get stuck moving left and I was unable to move at all. I had to refresh the page to get it working again. I'm not sure what was causing it, but it happened several times. I wasn't able to intentionally reproduce it.
Overall, this is a decent arcade shooter that's fun to play for a few minutes at a time. Nice job!