forget the last idea...stupid one...
I dont agree, the overall shape of the tower is nice and I like the corners!
The windows and entrance however should be smaller to fit in a bit more in the OpenTTD world and the white walls should have some more texture.
Also the battlements on top should be narrower/smaller/thinner (hope you get my drift

) to fit into the OpenTTD world, they are as big as a car now

So, dont give up on this yet!
this one is better:
A Stationbulding for TownWalls....
With this I have some more issues....
First I have to ask, is this a 3D model you found on the web and have converted to OpenTTD-scale and perspective?
If so, was the original model copyrighted?
If it is entirely your own work, then I have some other things to point out (and I apologise in advance for maybe being a bit harsh and very strict, but sometimes I take pixel-art a bit too serious

I only point out these things so that objects will fit in more into the OpenTTD environment):

- Townwall004.png (48.64 KiB) Viewed 4141 times
1. Strange greenish blobs. Probably caused by shrinking/reshaping. Very ugly, try to avoid those effects or correct them.
2. That sunny part of the roof could use some more texturing. Try to avoid drawing large single color areas.
3. The bottom should have straight lines, take a look at the green and yellow tiles in the right of your picture to see how straight lines are drawn in OpenTTD. By that I mean the general lines, the entrance in the middle should indeed poke out a bit, but also with a straight line at the bottom.
4. This is still a matter of opinion and taste and also depends on what views one has regarding the position of the sun in OpenTTD, but in my opinion, the dome should have a bit more shading in the general area of the blue circle. Difficult to explain, but a bit in the shape of a crescent moon, starting at the point on the left where the dome meets the building on top and ending at the bottom of the blue circle. The shadowline between those points then has a shape like this (so a curved line) I hope I explained it a bit what I mean

Rounded objects are very very difficult in OpenTTD!:

- Townwall005.png (24.53 KiB) Viewed 4141 times
Furthermore, the lines between the walls and the roof have strange colors. It looks like the blueish color of the roof has mixed with the grey color of the wall (probably also caused by resizing/reshaping). That doesnt look that good to me, keep it the same color as the walls.
I think that for the TownWalls objects this building is too large right now. However, maybe when it is reshaped to a maximum of 2 tiles and maybe with just two floors it can be used as a townhall or bank. But it might be usefull in the shape it is in right now for other projects.
So, I hope you see this as positive criticism. I think you have a lot of potential with the drawing!!
And I also think it should be a good idea if you start your own topic in this forum where you present your artwork, that way others can also discuss and help with your artwork and all your work can be found in one spot. Makes it easier to find later on. And dont forget to state under what license you want your work to be under (maybe do that in the first post of your thread), so that maybe many years from now others can still use your work!