You really nailed the optional theme here, like wow. The theme of connection really comes thru in the gameplay, and that's the mark of a good theme interpretation imo. Grats!

So far as feedback goes, I think a second pass at the artstyle is the only serious feedback I can give rn, since as much as I LOVE the Among Us cubes, a clean look would really make this game.

What a fascinating and challenging puzzle-platformer. The game's core mechanic is very easy to understand, yet actually executing it is a significant mental challenge. I felt a similar mind-stretching sensation to when playing Portal for the first time. The visuals are spartan, yet somehow match eerily well with the ominous, weighty sound design and haunting music, which prepped me suitably for the macabre ending. I especially like the audiovisual treatment of the bond between the siblings--the line changing color as it stretches is inspired.

My only bit of constructive criticism is that I still found the controls a little obtrusive long after I had figured out the puzzles, though upon reflection I would argue that taking my own skill into account is an important part of solving these puzzles. That is: "Now that I've determined a way to pull this section off, can I actually do it? is there a way to make it easier to execute?" Overall, this is a thoughtfully and beautifully designed game. Great work!

Out of all of the submissions I've played so far, this games truly feels like it encapsulates the word "Connection". The calming colors and mystical music combined with the simplistic designs of the levels makes the entire experience a calming adventure. The sudden change in vibe when the color of the connection goes from blue to red is a touch I especially like as the red contrast to the calming colors of the levels make for a sense of panic that instills a sort of terror that not only makes you afraid of losing the game, but afraid of separating these siblings.

 In games such as Ibb and Obb, A Tale of Two Sons, or even Jak & Daxter don't feel quite the same despite being games about playing as two to complete a level. I believe Lost Siblings feel special because the bond between these two aren't compliments to each other, their bond is quite literally life and death. And although there is no actual dialogue in the game, the bond we see between a blue box and a red box feels so loud and implies far more than words could actually describe. An Amazing game, thank you for the experience.

I was actually really impressed by the level design and mechanics going in! It was really creative and since our games were similar I was really interested by the spin you took on it. One think I think could be improved is that if the sibling on bottom jumps while the other is airborne, the other brother blocks his jump but it would be cool if they either bounced or the one on top got carried (or something to that effect)