Abandoning a good start

I started working on this project to learn more about the Phaser 3 game engine. I finished a prototype of the first level and I love how it came out. 

https://techhdan.itch.io/kirbit

Now that I'm more comfortable with the engine I'd like to shift my focus to a more ambitious game idea I've had for a while. Do you guys ever experience this? Being in the middle of game dev just to want to start another project. Do you guys ever come back to old projects? Do you usually work on multiple game projects at once or finish one first no matter how long it takes?