Some platforms had or have restrictions on what web APIs can be used (FB messenger games, for example), but those restrictions are typically tied to overall hardware limitations, which improve over time. All hardware, including mobile, is still getting more powerful year over year, and bandwidth is getting cheaper. It is certainly interesting, however I'm starting to doubt the necessity. It will perform even better once the assets are redone and optimized (at the moment the game uses some free asset packs).
Despite the download size it still loads and runs fast, even on low powered devices like entry level Chromebooks. Thanks to the assets, the download size is now 17MB.
This time, the game is 3D, uses full PhysX (from the server, not Unity), and our cloud physics/multiplayer system to drive the game logic. They were new to Unity, but we helped them along. They wanted to make a sequel to their game, and liked some of the things we did on kazap. We currently working on another game with a different studio. The retention numbers weren't great, but that wasn't the goal. The game made more money than it cost make and run, despite all the larger download size, though it only peaked at about 150k monthly users. With a little finagling we managed to get our bounce rates down into the low-20s and session duration was around 5 minutes. Once we added assets, the total download size came to about 8 MB, which is large, however it ended up not being as much of a barrier as we thought. Most of the logic for the game ran on our system online, even physics, so the client just had to handle inputs, decode the network stream, render, and perform smoothing and prediction. We used Unity's new webassembly support, which was experimental at the time, but it worked fine for us. We had a fair bit of fun playing, after all. We posted the game around in early 2017 to see how it would do. It worked without a hitch, even though we had to some work on our toolset to ensure web was properly supported. We built a game, ported it to Unity, and used Unity's webGL output to build a web version. Back when io games started to become significant, we decided to use the web as testbed for a multiplayer/cloud processing system we developed. We have been working with Unity for some time. It is making me wonder if Unity's Core Runtime will bring much to the table once it's fully realized. Unity's webGL implementation is rather good, at least in our experience with simple games.