What we've learned about each World Cup team after seeing them all once

Every participating nation has played at least once at the 2018 World Cup in Russia, providing a glimpse at each side's chances of progressing to the knockout stage.

Here's what we've learned through six compelling days of action:

Group A

Russia: Leading the tournament at the first bend with five goals in a one-sided drubbing of lifeless Saudi Arabia, host Russia surprisingly sits atop Group A ahead of Tuesday's critical clash with Egypt. A test against the Pharoahs will provide a better impression of Russia's outlook.

Uruguay: Despite an uncharacteristically poor outing from Luis Suarez, Uruguay earned three points against Egypt thanks to a towering late header from Jose Maria Gimenez. Even with some concerns lingering about his squad, Oscar Tabarez has a slew of midfield options ahead of a straightforward date with Saudi Arabia.

Egypt: It's hard to gauge how good Egypt is without Mohamed Salah. However, despite the back-breaking defeat against Uruguay, Hector Cuper's lot has plenty to feel positive about, namely the performances of shot-stopper Mohamed El-Shenawy and right-back Ahmed Fathy.

Saudi Arabia: This is not going to end well for Saudi Arabia. After allowing five goals to a Russian outfit that entered the tournament as the lowest-ranked side, Juan Antonio Pizzi's charges have to keep Suarez, Cavani, and Salah off the score sheet. Good luck with that.

Group B

Morocco: It's hard not to feel gutted for the Atlas Lions. An expansive, attack-minded showing against Iran saw Team Melli snatch the three points with Aziz Bouhaddouz's 94th-minute own goal. Next up for Herve Renard's side is a pair of must-win matches against Spain and Portugal.

Spain: Even amid the frenetic draw with Portugal, Spain made a good account of itself. After benefitting from a renewed tiki-taka approach under Julen Lopetegui, Diego Costa led the charge with a robust, vigorous performance. The knockout stage beckons for the 2010 winner.

Portugal: Two years after winning a major tournament despite some underwhelming displays, Portugal looked threatening against Spain, and like its Iberian foe, Fernando Santos' men experimented with different plans of attack. It also helps when Cristiano Ronaldo is unstoppable.

Iran: Carlos Queiroz's charges did what Carlos Queiroz's teams do, and despite not registering a shot in the second half, Iran stole a victory thanks to a catastrophic late own goal by Morocco. It would be a shock if Iran earned a point off either Portugal or Spain.

Group C

France: Les Blues weren't exactly firing on all cylinders, but the mark of a great team is getting results without a peak performance, and France did exactly that against Australia. Questions about Didier Deschamps' best starting XI and formation still remain.

Denmark: It's remarkable how quickly a footballer's fate can change. Just ask Denmark's Yussuf Poulsen, who went from zero to hero by committing the foul that led to Christian Cueva's horrible penalty miss, then later he scored the match-winning goal.

Peru: Peru fell short despite outshooting Denmark 17-10. Paolo Guerrero's slick backheel attempt sliding narrowly wide of the far post was the lowest moment during an unlucky day. Everything now rides on Thursday's tilt with France.

Australia: Full credit to the Socceroos for displaying heaps of resolve after the interval against France, though while Denmark and Peru were hardly convincing, it's tough to see Australia progressing from the group. A positive result against Denmark on Thursday will change that in a hurry.

Group D

Argentina: Much has been made of Lionel Messi leading his Argentinian teammates into yet another major tournament, but the Barcelona star didn't exactly help his cause against Iceland. With a brilliant attack, questions at the back and a jittery 'keeper, it's the same old same old for La Albiceleste.

Croatia: With Argentina stumbling out the blocks, Croatia's dark horse status and chances of topping Group D have been handed a massive boost, especially after registering a clean sheet against attack-minded Nigeria. The true test will come Thursday against Messi and Co.

Nigeria: An own goal and a penalty were the difference against Croatia. With Argentina and a spirited Iceland side left on the slate, everything is in play for Gernot Rohr's Super Eagles now. Victor Moses and Alex Iwobi continue to be the biggest threats, with the former thriving in an advanced role.

Iceland: Faced with a challenging group and concerns over Gylfi Sigurdsson's fitness, Iceland was largely counted out after December's draw, despite being the favourite among those without a rooting interest. How foolish was that, especially after a resolute performance against Argentina? The sky is the limit with this lot.

Group E

Brazil: Well, that didn't quite go according to plan. Tite says Neymar's injured right foot is not 100 percent, and after limping during the draw with Switzerland, there are concerns the Paris Saint-Germain star is not at his best.

Serbia: Mladen Krstajic's towering lot bested 2014 quarter-finalist Costa Rica courtesy of Aleksandar Kolarov's free-kick. The tallest team in Russia, Serbia is a sleeper pick while guided by a robust backline and midfield, and star-to-be Sergej Milinkovic-Savic.

Costa Rica: Four years after shocking football by finishing atop a group that featured Uruguay, Italy, and England, Costa Rica looked worryingly flat against the Serbs. With Brazil and an industrious Switzerland team on the docket, Costa Rica faces a tough road ahead.

Switzerland: What Vladimir Petkovic's squad lacks in flair, it makes up for in cohesion and spirit. With Valon Behrami turning back the clock through his ankle-bruising performance, along with solid displays from Blerim Dzemaili and Stephen Zuber, the Swiss could cause trouble for Serbia.

Group F

Sweden: Sweden topped a lifeless South Korea by a narrow score thanks to a penalty, with Marcus Berg and Ola Toivonen looking like the two mediocre forwards they are. It was all painfully boring.

Germany: Die Mannschaft's midfield is deservedly the source of derision following the shocking loss to Mexico. While the reigning champion should still get out of the group, that result could be more a measure of how poor Sweden and South Korea have played, and not how well Jogi Low's lethargic troops are performing.

Mexico: Hirving Lozano, take a bow. The PSV star's performance against Germany was the main takeaway, but credit goes to Juan Carlos Osorio for taking a risk, and to Chicharito, Carlos Vela, and Miguel Layun for filling out a lethal front-four.

South Korea: After slumping to a drab defeat in what should have been the easiest test of three group-stage matches, South Korea looks set to finish at the bottom. It would help if the Taegeuk Warriors registered a shot on target versus the Swedes, or if Lee Keun-Ho and Kwon Chang-Hoon weren't injured.

Group G

Belgium: The second half against Panama on Monday will only boost Belgium's World Cup hopes amid rumblings that Roberto Martinez is not the man to lead the Red Devils to a maiden-tournament win. A front-three of Eden Hazard, Romelu Lukaku, and Dries Mertens looked marvelous at times.

England: If the first 20 minutes of the 2-1 victory over Tunisia is any indication, this is a different England side. The back-three gave Harry Maguire opportunities to surge forward, Harry Kane was clinical, and Gareth Southgate has a slew of midfield and attack options that other managers envy.

Tunisia: Disappointing stuff from a Tunisia side that looked good in the lead-up friendlies. There's a bit too much for Wahbi Khazri to do without any decent service from the midfield four, and with just one shot on target against the Three Lions, the Eagles of Carthage have some work to do.

Panama: After fighting tooth and nail to stay in the match with Belgium, the rift in pedigree was evident after the break. Lovely story for the World Cup debutant Panama, but it's a stretch to think a team that starts Blas Perez and Armando Cooper has any chance of upsetting England to reach the last-16.

Group H

Poland: Maybe there was a reason Poland came into the tournament without the typical "dark horse" label that is usually attached to Adam Nawalka's team. The service to Robert Lewandowski was severely lacking in the Group H loss to Senegal, and the injury-induced absence of Kamil Glik from the starting XI loomed large for a side that looked shaky at the back.

Colombia: It's almost impossible to make any assertions about a team that played about 88 minutes of its opening match with 10 men, but Colombia, the Group H favourite coming into the tournament, is in big trouble already. James Rodriguez isn't fully fit, Davinson Sanchez struggled against Japan, and now midfield anchor Carlos Sanchez will be banned for his straight red card.

Japan: Widely tipped to be the weakest team in Group H, Japan's 2-1 win over 10-man Colombia was aided by the numerical advantage, sure, but Akira Nishino's side defended well, dictated play in midfield, and with Keisuke Honda and Shinji Okazaki both starting on the bench, there are solid options should a tactical change be needed at some point going forward.

Senegal: All aboard the hype train. Senegal, one of the coolest teams around, opened up its World Cup with an impressive win, and with the combination of blistering attackers, all-action midfielders, and a solid backbone anchored by Napoli colossus Kalidou Koulibaly, the Lions of Teranga showed why they were being tipped as an under-the-radar threat ahead of the competition.

(Photos courtesy: Getty Images)