Which engine is best for developing games like OpenTTD, Mashinky?

Question

Game development

Good afternoon. Tell me, which engine to choose for developing a transport strategy like OpenTTD? The only condition is that it be 32-bit, and preferably (but not necessarily) free.

Answer 1

Just for reference: OpenTTD is built on SDL, but it's not an engine, it's a library, and a pretty low-level one at that.

Answer 2

Unity3d, in the Asset Store you will find many free assets to make this kind of game easier.