Golf ball comprising layer(s) consisting of a mixture consisting of: i) ethylene acid copolymer(s) and/or ionomer(s); ii) polyethylene(s); iii) polymeric epoxy crosslinker(s); and iv) compatibilizing polymer(s). The ethylene acid copolymer(s)/ionomer(s) and the polyethylene(s) may be included in a blend in a wt % ratio of from about 85:15 to 55:45; the at least one polymeric epoxy crosslinker and compatibilizing polymer may be included in amounts, based on 100 parts of the blend, of from about 2.0 to about 10.0 parts; and from about 1.0 to about 10.0 parts, respectively. The polyethylene may be polyethylene butene; polyethylene hexene; polyethylene octene; and combinations thereof. Each ethylene acid copolymer, polyethylene, polymeric epoxy crosslinker, and compatibilizing polymer has a density less than 1.0 g/cm3. The mixture is moldable and meanwhile possesses similar desirable CoR, DCM compression, Shore D hardness, and Shore C hardness as a mixture consisting of ingredients i), ii) and iv).