I gave Heaps a try because I wanted an engine that wasn't tied to any specific editor but ultimately gave up on it. I put in a few weekends of effort but the documentation was just way too minimal [0] and turns out it can't really target mobile platforms out of the box [1]. Even the main developer apparently just outsources mobile ports to another company.

[0] - https://heaps.io/documentation/h2d-introduction.html

[1] - https://github.com/HeapsIO/heaps/issues/422