Something I can play in a window with just the mouse

[MissChief]

When I'm watching something on my PC I tend to have it in the corner and have been playing OpenTTD in a window on the left of the screen but I'm getting a bit bored with it.

So I'm looking for something new to play. Ideally just mouse and in a resizable window. Any ideas or recommendations?

 

[MissChief]

I might see about Cities Skyline after I come back from the Grand Prix. Thank you all.

 

[MissChief]

Eve online

Tried it once. Spreadsheets....in....SPPPAAACCCEEEEEE!

And the idea of losing everything I've worked for in an instant doesn't appeal.