I'm mainly interested in feedback regarding the game feel and mechanics.

1. Do you think it's easy (or could be with a little practice) to determine where the enemies are coming from? 
2. Did you understand how each enemy behaves? if not, wich one?
3. Did you feel like you were hit in an unfair way? How? 
4. How do you feel about having to spam the shoot buttons? Can you achieve a consistent fire rate? 
5. Do you think adding a special action like a dash or supershot would make the game more enjoyable? Do you have any creative ideas?
6. Please share your highscores and levels. 

If you have any aditional feedback you want to share, please do. Probably the worst parts are the visuals and audio, so feel free to sugest any ideas to improve it, just keep in mind it must be kept simple, I'm not an artist o audio designer.

Thank you for your time! 

Here's the link to the game: https://juritobi.itch.io/martian-killing

The game looks pretty good

The concept is simple but the mechanics are great! Liked the contrast between different types of enemies and their movement patterns. I don't usually play these types of games so I didn't get beyond level 3.

The visuals are simple but they are easily distinguishable and fit the retro aesthetic. I wouldn't change them too much, maybe add some ship components to the more basic ones. The player character in particular needs to be distinct and have a more recognizable profile (even a simple one).

As for sound, the background music and sound effects work well together and play at a good volume.

I liked the layout, but I'd suggest a more atmospheric UI than just plain text in the default font. You could also add a start menu with some options.

For more people to start playing your game, you should use a more attractive cover image. Even a screenshot with some filters is better than the coloured squares on a black background you have right now. You could start a devlog in the community to document your progress.

The game needs polish before people will play it, but it has a lot of potential and I genuinely enjoyed it. Ping me if you have any updates and I'd definitely play again.

2,324 LV4. I would add a zero to the score. Adam Millard made a video on how people like getting big numbers even is the numbers are arbitrary. 2,324 is good. 23,240 is even better. I would also make the score bigger on screen. I would also add a high score to the board (like 1.000) to motivate people to play past their first game. If you get 600 your first game you would think I can beat 1,000.

 The game felt fair and is well made. It is not super exciting. Maybe add score boosters or pickups that will freeze your multiplier, but have them spawn in dangerous places. Try to push players to take risks so they need to get better to get a higher score. Or don't. What do I know. 8/10