Nice work for a first game! Jumping is nice and responsive, fun sfx.
Collision box for the spikes seemed just a tad too large -- I found myself jumping at spots where I thought I could make it but ended up losing right as I jumped.
In a few spaces I felt like I was making a bit of a leap of faith since the platforms were offscreen. At one point there was a mug just off the platform, so for that one I could tell there would be a platform below. Would have been good to place mugs at all those "drop off screen" locations to show the player where they should jump at.
Enabling collision on the particles so that they disappear when hitting the ground/player would have been a nice touch. On the menu, you could also have had the particles fade out rather than disappear immediately.