Being raised playing beat 'em ups, I was ecstatic to have a chance to revisit my childhood with Marvel Cosmic Invasion. My favorite game from this genre is The Punisher, another Marvel game and arguably the best beat 'em up ever in terms of quality and mechanics.
But after so many years, and frankly many disappointments, I finally have that feeling of playing those games from the arcades (who remembers Cadillacs & Dinosaurs and Final Fight?). Marvel Cosmic Invasion goes straight to that '90s arcade feeling, so don't expect Hollow Knight or Hades-level of difficulty (frustration?). This is all about having fun, and boy, did I have fun with this demo!
All Characters in Marvel Cosmic Invasion Demo

Marvel Cosmic Invasion demo has 9 playable characters: Captain America, Nova, Storm, Wolverine, Phyla-Vell, Spider-Man, Rocket Raccoon, and She-Hulk. They have different fighting moves, forcing you to employ different fighting strategies depending on which character you use. Some characters can fly, which helps when you're facing flying enemies, while others can throw opponents around, which is super helpful.
It would be nice to see their stats (such as strength, speed, and range) in the character screen, to make things more transparent. Perhaps we'll see this in the final version; we'll know more when 1.0 is released.
As you can see in the image above, 4 players can play co-op, each having two superheroes as a tag team. It's actually a great solution to have switchable characters, as that gives you options for interesting combos. This is similar to Mortal Kombat's Kameo Fighters, with the difference that both characters are fully playable here, and you can switch back and forth instantly as much as you like.
This way, you can combine ranged and close combat characters, creating an ultimate fighting team. For example, Rocket Raccoon has the biggest range, while She-Hulk is super tanky but has a very short punch reach. But when you can switch them all the time, suddenly, She-Hulks biggest flaw is negated.
Level & Enemy Design

Marvel Cosmic Invasion demo offers only two levels: New York City and Helicarrier. While I would love to have more, it was enough to get a feel for that classic 2D sidescrolling level design. Of course, every good beat 'em up needs a construction yard, holes, barrels, and, of course, food power-ups hidden in garbage cans.
New York City is a classic level where there's not much to interact with, giving you an opportunity to focus on warming up and learning controls and superhero powers. On the other hand, Helicarrier level has holes you can fall through, an elevator fight, and guns you can use to take down enemies. Interestingly, the second boss was much easier than the first, although both were relatively easy to defeat.
How Challenging Are Enemies in Marvel Cosmic Invasion?
Enemies will force you to use more than one attack button, as they can block shots, fly, run into you, shoot, and more. I had some trouble at first with flying enemies, as some characters are not really good at dispatching them. I'm looking at you, Spidey! Combat is always challenging, but most importantly, fun, so you'll never feel overwhelmed. Of course, the final version of the game will probably force me to eat my controller, but in this demo, I was enjoying my time, and you should too.