Need help optimise simple tiles that consume a lot

Ya the 2D grid is actully a little bit of and 3D grid, just that for the moment there is only one height per tile (and that might change). The final idea is to be able to add the grid so it fit the ground, meaning even if the ground is kinda wawy it won’t look like a wierd box over it, and that the height is also significative of the distance between 2 tiles, so if one have 1 of height and the next have 2, you can still pass it but it will cost you 1 more movement point.

But the more am coding it the more difficult it seem to get, so i might reconsider all of this xD

2.5 D is probably the common term for what you are describing. Most heightmapped terrain is like this too… just a grid mesh with elevation at the corners.