Things I do not love so much: it appears to have serious performance issues, at least in simulator mode. Though the UI is responsive, my screeps routinely stopped for several seconds with a "CPU limit exceeded" message printed to the console. How is that possible, given that all I was doing is playing the tutorial and I had only a handful of screeps on screen? I am hoping they haven't backed themselves into a corner here by building on Javascript and HTML rather than simply doing a desktop app, because the game mechanics have a lot of promise. I tried pressing the button to double the game speed but it didn't seem to help much (I guess that won't function when connected to a server).
Also, no way to zoom the playing view? The screeps were tiny on my retina macbook. I could barely see what was happening.
But biggest dislike: Indiegogo to complete the game? I'd have preferred a more traditional model in which maybe there are fewer features to start with, and they simply charge me a monthly subscription or a one-off purchase price. Crowdfunding is best used IMO to develop public goods or public infrastructure but Screeps is just a plain old proprietary game - nothing wrong with that, but it seems somehow bogus to expect people to give you the money to finish it, for free. Moreover it sounds a lot like they haven't actually got the server side mode working yet. That's fundamental to the whole concept. If they didn't build it yet, they don't really know if they can - what if the game just doesn't have good enough performance to work well? I think I'll pass on this crowdfunding campaign, myself.
Still, I'm looking forward to when they have the problems worked out (if they can) and I can just pay an honest buck to play. I can imagine it being a huge time suck :)