- Estimated achievement difficulty: 3/10 [Achievement Difficulty Rating]
- Offline: 16 
- Online: 0
- Approximate amount of time to 1000: 8-12 hours [Estimated Time to 100%]
- Minimum number of playthroughs needed: 1
- Missable achievements: None [level select]
- Does difficulty affect achievements: No difficulty option
- Unobtainable/glitched achievements: None
- Extra equipment needed: None
DLC: Portal Proficiency
- Difficulty: 4/10
- Time to 170: 4-5 hours
- Unobtainable: None
Welcome to Bridge Constructor Portal, the third entry in the series. This entry unsurprisingly combines the gameplay of Bridge Constructor with the obstacles and mechanics of the Portal series, namely Glados as the AI guiding you, portals themselves to go through, sentry guns, and other items. If you've played other Bridge Constructor games, there is one really nice thing about this game: no budget! You can build to your heart's content without being restricted by a dollar value. Instead, the challenge in this game is entirely in making use of minimal anchor points for your structures and with trying to navigate the portals and obstacles. Achievement wise, you'll have to complete all of the levels with the "hard" setting, snag a couple easy miscellaneous achievements, and then grind out one or two others. Let's get started.
Your first and main order of business is to complete all 60 levels. Completing a level with your standard vehicle will then open up the option to try the level with a convoy of vehicles. All 60 levels need to be completed with the convoy of vehicles, so your constructions need to be pretty rigid and sturdy to withstand the convoys, which can be upwards of 16 vehicles in a row. Thankfully reliable level solutions are available and can be found in the "0% Non-Delivery" achievement solution.
One thing to note: since this is a physics based puzzle game at heart, it's possible that vehicles will behave differently for you with a structure that looks similar, so don't be surprised if you need to tweak your construction a bit here or there to get it to work. Or, run the vehicles a couple times and see if it turns out slightly differently.
This step will take a solid chunk of time because even with solutions, it takes a little while to build the paths in some levels. Just be aware you don't typically need to replicate level solutions exactly. Even so, expect to spend quite a few hours getting each level just right.
Once you've completed all 60 levels with the convoy, all that's left is mop up and then grind.
At this point, if you haven't unlocked them or done them yet, you can now very quickly and easy knock out "Centrifugal Convoy Adjustment System," "Entry-Exit Relay Repeater System" and "Aerial Mobility Support System." Refer to the guide for levels in which you can easily get these three.
If you're really good or just didn't let attempts play out until cars were destroyed, you may still need to grind some "deaths" for "You monster." but you'll definitely need to grind out "For More Science!" Refer to the guide for which levels to grind them out in quickly. That should wrap up your completion.
Portal Proficiency DLC
The Portal Proficiency DLC comes with 30 new levels, as well as one brand new mechanic: you place portals wherever you want, instead of them being fixed. This makes for a whole new level of challenge in this DLC. Like all content though, a guide can be used to replicate constructions. Like the base game, you'll need to complete all 30 levels like normal and with a convoy. Refer to the guide for level solutions for all 30 levels with convoys.
Once that's done, there are a handful of miscellaneous achievements to unlock. You'll likely get the majority of them as you progress. If you're missing any when you're done, such as destroying 50 test vehicles (which is the only one you probably won't get naturally), then refer to the guide for where to best unlock each achievement, wrapping up this DLC.
Bridge Constructor Portal is another solid entry in the series. The budget limitations have been removed, allowing you to rely entirely on your building and engineering prowess to conquer each level. Additionally, you've got the added comedic element from Glados to lighten things up as you go. Like other games though, you can use level solutions to get through the game relatively quick, but constructing each level will still take some time.
[XBA would like to thank Necrophage33 for this Roadmap]