As I mentioned before, I'm pretty sure a tier list is gonna come to order sonner or later, so as of today, I will reveal the demo's tier list (From what I see so far).
1. Red & Pikachu- due to assistment and power
2. Yugi and DMG- due to assistment and power
3. Sakura- Combo abilities are amazing
4. Ryu- Can make blow after blow
5. Mario- Amazing combo abilities
6. MegaMan- Projectile mass is unbearable
7. Link- Bombs that hit have knockback as well as god-like sword ledging
8. Tron Bonne- Drill spamming makes it hard to attack back
9. Meta Knight- Amazing combo abilities and jumps
10. Sonic- Speedy but has low stamina
11. Z.S. Samus- Attacks tend to have small power, but good comboing
12. Cpt. Commando- Attacks are powerful, but speed is poor
13. Bowser- Easy target, but overtakes that with power and a little bit of speed
14. Viewtiful Joe- Terrible, attacks are weak as well as stamina, I'm working on it.
There you have it!