When Microsoft began calling for people to test its Project xCloud cloud gaming service last month, I was skeptical of how it would perform over the toughest stress test you can throw at it: a cellular connection. That’s why I was surprised at how well it works.

I’ve been trying the Project xCloud beta off and on for more than a week now. Keep in mind that Microsoft is actually testing two betas at the moment: Xbox Console Streaming, where you’re streaming games you own from your Xbox to a mobile phone or tablet; and Project xCloud, which takes a pre-selected batch of four games and allows you to play them over a wireless connection. I’ve tested only the latter, though the former is now live for Xbox Insiders.

Let’s pause to talk about lag

In both cases, a pleasurable gaming experience boils down to one factor: latency, or the time it takes for you to react to a given scene and input a controller movement or button press, and for the game to respond accordingly.

On a “local” console or PC, that latency or lag is almost nothing. Though some professional gamers will use wired mice to minimize the lag that can occur between the wireless connections on a PC, lag is rarely noticeable on single-player games if you’re running on an up-to-date machine. It becomes somewhat worse if you’re playing a multiplayer match online, even if you’re on a high-speed wired connection. OnLive, which pioneered cloud gaming before flaming out, succeeded technically but failed as a business operation.

It becomes even more pronounced if you’re playing games remotely, over a wireless connection. Microsoft implemented game streaming on Windows 10 in 2015, where you could take a Windows PC and play games streamed to it from a console elsewhere in your home, over a wireless connection. (Xbox Console Streaming is essentially an extension of this.) Over a wireless LAN, lag increases even further.

Theoretically lag should be the worst of all over a cellular connection. On Project xCloud, it was surprisingly not too bad.

Mark Hachman / IDG Project xCloud is Xbox: if there was anything different about what I saw on my phone’s screen versus on my console, I didn’t notice it. But keep in mind that you’ll need to squint at some of the tiny bits of type, too.

Remember that playing games over Project xCloud is going to be an entirely subjective experience, dependent upon your location, proximity to a cellular tower, your carrier, network congestion, and other factors. Based on my experience, here’s what I saw.

Playing games on xCloud: not bad at all

Project xCloud gives you access to four games: Killer Instinct, Gears (of War) 5, Halo 5: Guardians, and Sea of Thieves. Organized like this, the games range in pace from KI, which is quite “twitchy,” down to the relatively moderate Sea of Thieves. My oldest son and I played all four, though I spent less time with Sea of Thieves because I wanted to see how the service accommodated faster games.

My test bed was a OnePlus 6T smartphone running Microsoft’s Game Streaming Android app over an unlimited T-Mobile connection, and a standard Xbox controller. Just for fun, I tested xCloud not only while connected via Bluetooth, but also separately with a USB-C dongle. Both worked well.

Mark Hachman / IDG No, xCloud isn’t as good as a local console, and may never be. But depending on what you’re playing and over what connection, it’s okay.

I was surprised by how reasonably three out of the four games played. Killer Instinct was a challenge, in part because of how unfamiliar I was with the game’s controls. Unquestionably, xCloud introduced lag into simple moves and punches, though not as much as I expected over a cellular connection. Even on a local connection, I probably would have tended toward button-mashing. On xCloud, I found that to be the most effective strategy regardless.

With Gears and Halo, though, I was truly surprised. While Halo is a first-person shooter, and Gears tends to be played in third person, I was able to play Gears 5 fairly well in multiplayer Horde mode throughout the first few levels—contributing to my teammates, shooting accurately, and so on. My son played about fifteen minutes of Halo and did just fine, without complaining of any lag. Peering over his shoulder, he didn’t seem to have any issues taking on the Covenant in the opening mission.

The strength of my cellular connection, though, did make a significant difference. Testing during my son’s soccer practice, I experienced decent “ping” times (milliseconds of latency) in the 50s and 60s, as reported by Gears 5. At home, on the periphery of a couple of cell towers, pings stretched to 90 milliseconds, and loading times also climbed. Playing over Wi-Fi at home reduced the latency down to the 40s and 50s in milliseconds once again.

Sea of Thieves, a large multiplayer fantasy pirate simulation, is somewhat slower-paced to begin with, and I didn’t spend much time poking about its gorgeously rendered seas. I will say that, perhaps due to the slower pace, SoT felt a little laggier than I remembered, playing on the Xbox console itself.

All of this sidesteps my problem with Project xCloud at the moment, though, and that has nothing to do with lag. It’s the challenge of compressing games that could be, and usually are, played on large displays in the family room, into a tiny fraction of that screen space. Microsoft sells a phone clip that attaches to your Xbox controller, though my smartphone car mount did just fine. A phone can be balanced against everything from a laptop screen to a couch cushion. Over time, though, simply squinting at games wore down my eyes quickly, to the point where it became a chore rather than a pleasure to play them.

That, of course, begs the question: If a phone is too small to enjoy playing games, what other options are there? Tablets, of course, would be a natural choice, and there is an Android app, but nothing for iOS. I have a suspicion that Microsoft sees xCloud as perhaps the killer application for foldable phones like Microsoft’s Surface Duo.

There’s still the question of data. I didn’t track how much data xCloud uses, but I have an unlimited connection. Not everyone does. Microsoft also has not enabled Project xCloud to stream to a remote Windows PC via Wi-Fi or cellular.

It’s not entirely clear how Microsoft will price xCloud, or how it will be deployed. Making it part of Game Pass Ultimate seems to be a popular guess. Let’s hope that it’s a “try before you buy” scenario, or that Project xCloud is bundled with Game Pass, eliminating the “do I really want to pay for this?” question.

Since I’ve tested OnLive before, some of the “magic” has gone out of cloud gaming. Playing over cellular, though, has put some of it right back. Being able to toss a controller into a backpack and play in a few spare moments is kind of amazing. Maybe this is the future, after all.