Here is small demo of a potential 2D side-scroller level made in Unity with help from a YouTube playlist created by CasanisPlays: https://www.youtube.com/playlist?list=PL2cNFQAw_ndyKRiobQ2WqVBBBSbAYBobf.
The demo includes basic movement controls, the ability to shoot arrows, obstacles and two enemies. One enemy which charges towards the player character when the player gets too close and one which shoots projectiles when the player is too close.
The win condition is activated once the player gets to the chest and game over can occur when falling of a ledge or taking too much damage.
The purpose of this project was to gain an understanding of the 2D workflow in popular game engines as I plan to produce a full 2D side-scroller similar to what is seen and was having trouble choosing whether to use Unity or Unreal Engine.
Usually I work in Unreal Engine, but for this project I found Unity to be better suited for 2D development. A similar level was also prototyped in Unreal just to confirm which had the better workflow, shown towards the end of the video.
While it is probably possible to make the exact same game in both engines. I simply preferred the 2D workflow in Unity, especially as Unreal has pretty much abandoned their Paper2D library.