Not bad for the first game! Tips so you can improve:
- Try to find a name for your game. Even it is something simple like "Yellow Knight". Gives the game personality :)
- Music. Game without music feels empty, so try adding music, but not too loud. I appreciate the SFXs :)
- Font for texts. I would recommend dafont.com to find Fonts. Really easy to download and use with Unity's TextMeshPro. But it is not important for the first game. Just a tip :)