I played this on my own and the controls took some time to get used to -- although I am extremely thankful you took the time to add controls pop-up because the keybinding wasn't very intuitive, and I would've struggled a lot more if it weren't for those tips, that's a 5/5 in game design right here ;).
I like the stealth mechanics and how you have to use the small brother to trap the guards with boxes. Graphics are simple but the post-processing add a lot to the whole picture and the game is pleasant to look at. I also like how you built a small narrative with the thumbnail and would've loved to see that expanded because with things like an intro cutscene. Only real problem I encountered is that the webgl version was stuck in an endless loading screen after the 3rd level so I couldn't complete the game, which is a shame because I would've loved to see the ending. Great work!