Fortunately for me, I used free assets for the graphics (can't really draw and didn't have any artists available to partner with me) so I wasted most of my time on level design and mechanics.
This was my first attempt at a 2D game too and Unity was helpful until it wasn't, so there was a lot of downtime learning tilemaps for example. I didn't really understand layer sorting so I was a bit confused when I hit 'Play' and the "decorations" of the level magically poofed xd