Roads of Rome: Portals Collector's Edition

I was a huge fan of the old Roads of Rome series and was delighted to see this title, with many of the old sound effects and musical flourishes even. This game is quite fun and challenging, with levels that take 20 minutes or so and require a lot of attempts and careful resource allocation. Unfortunately it is also INCREDIBLY buggy - if I play more than one level at a time it starts glitching graphically (white boxes popping up in place of some of the animations) and mechanically (mousing over a task no longer shows resource requirements, etc). Even though I've learned to quit the game and restart between levels, sometimes it gets going before I even finish a level. There's also at least one "extra" level that is locked when it shouldn't be (supposed to unlock after level 20, which I finished a long while back). It would be great to see some patching to stabilize this thing, but it's very fun nonetheless. Would be 5 stars for me without the glitches, which fortunately don't make it unplayable for me but are certainly very annoying.