The latest developments at attempting to minimally extend general relativity such that the theory exhibits some concept of limited curvature are presented. The underlying question is whether one can find a healthy semi-classical theory as an effective bottom-up description of quantum gravity that admits non-singular solutions. Focus is given to the Cuscuton (and its generalizations), an incompressible scalar field that modifies the dynamics of general relativity without introducing any new degrees of freedom in the unitary gauge. Formal aspects of the theory and phenomenological implications in the context of cosmology are presented.