the low ratings mostly come from the Squaby comments that it has just one level and is too hard. Also, due to the many particle effects played simultaneously it may get a bit laggy with >15 towers and >30 squabies in the scene. We are working on improving these issues, however, they can be handled by our customers already by limiting too many particle effects and by testing the particle effect performance with the Particle Editor (we will release a standalone app for the App stores for on-device testing soon!). On Android, there was a bug when Android 4 came out leading to a crash which unfortunately brought us some bad reviews, although we fixed it within a couple of days.
Overall, the V-Play games Squaby and Chicken Outbreak have a rating between 3.9- 4.4 on iOS & Android which is not that bad I think. We are putting more effort into improving the engine than improving our games, but especially for Squaby we already added the level editor so more content is available and more interesting additions are in the works.
The other games made of Pro customers of V-Play (also see our upcoming showcase section here) are performing well on the App stores with avg ratings >4.5 across the stores.
If you have more feedback for the games, please let us know here.