Extremely cute presentation! I love the colour scheme and the character animation. I have to say, this is a huge amount more ambitious than my first ever game. :') Well done, seriously. Sound effects and music, restart points, double jump, collectibles, enemies, even a boss battle... it's like a full-fledged platformer.
The jumps definitely got tricky towards the end, so I was very grateful for the restart points and unlimited retries.
Possible bug - After I defeated the boss, I died, and then the boss's projectiles were still spawning.
Got vibes from this of platformers I used to play - Mario, Sonic, and the like!
Finally, aww, wow, the backstory for this game is extremely sweet. I love it!! Best of luck to you and your wife and Dany on your game development journey! :)