Fun entry! I played "Merge to win" for like 30 minutes and it was very relaxing for my brain. I always loved physics interactions in video games, and I think it encapsulates what's so fun about it. Those "pop" sound effects are just cherry on top. Survival mode is fun as well, it's amazing to see how funky physics behave with those attractions, but I'd recommend making a barrier of some sorts, or a magnet to map's center, because they would just keep flying out of the distance, meaning I would never lose.
For the "Merge to win" mode, my only complain is that some colors are kind of hard to distinguish - purple and pink are very similar to each other. I'd recommend messing around with different patterns or something. I see you've started on this variety by making some materials unlit, but I think more variation would be appreciated so types of cubes can be easily recognized, especially those at low levels.