Wow, this is some lengthy feedback! I appreciate it so much!
Another user mentioned that the symbols could use a flickering effect as well, and I definitely agree with that since not having any warning could lead to some unfair deaths.
I also agree that the game does need some form of coyote time, this is on my list of things to add when I re-ramp the controls after the jam ends.
The reason for the particle effects you're seeing is to visually enhance that the player is moving around instead of having just a static background. I figured it would save much more time than to add a background texture while keeping the graphics minimal style... HOWEVER, there is nothing in the game that mentions as to why there is yellow dust floating around. So there does need to be a future explanation of what the dust particles are and why they are floating around. I do plan on having this game take place on a small planet floating in space in the developmental future, so I'll probably need more visual enhancements to show that's the location each level is on.
The ground does look a bit too white, and it really could have used any sort of texture. At the time of this game's creation I have not learned how to use the tileset generator yet, which is something I should really get into if I want to continue advancing with pixel art.
With the skull spikes, I was originally going to have it so that touching the side of them doesn't kill you. However, I also had to deal with making sure the player doesn't climb on top the very edges of the hitbox where they don't end up getting killed. Since I was running low on time, I just had the hitbox go around the skull spikes and figured that the skull symbol would be enough for players to know not to touch them at all. Perhaps I'll make a variety of skull spikes where the spikes surround all sides to deal with this problem until I can get it fixed.
This is a lot of helpful information I'll take into consideration. Thank you for taking your time to write this long critique.