My very first impression was that the water animation on the start screen was crazy impressive. All the special effects for the characters were really impressive. Some of them needed tuning for game feel, but for looks they were top notch. Also, all four characters look great. Did you make them all yourself? They look professional. 

I happened to have a group of 9 year old boys walk behind me while I played and they all really liked the look of the Battle Mage in particular.

Others have already mentioned the camera controls and I saw a reply that you know it's an issue. I do want to reiterate that solving the camera issues is the most important thing you can do next. The floaty,  unintuitive controls were giving me motion sickness and I still feel  queasy. I also really struggled with the jumping with the camera and never made it to the end of the level with any of the characters. 

When I tried the gunner, most of her skills didn't seem to shoot anything and her animation had her move her gun to the side. Just maybe a bug to keep an eye out for.

The last note would be I would love to have a hint (doesn't need much at all) of what the intent of the game is. Is there a story going to be connected to these characters someday? The title screen seemed to imply there might be, but the level felt like a tech demo with no particular purpose beside testing out the characters. It's fine either way, but I think a little clarity there could make a big impact.

A lot of content. Different characters with different enemies, a big level to traverse through. No enemies though. Would be nice if you added enemies before the boss. Soundtracks were really good. 

The main problem this game has would be the camera control. I had a hard time navagating the world because it was hard to: aim skillshots, jump on platforms, face the boss (omg half of the boss fight was spent trying to get the camera to look at the boss and to get the character in position to aim skillshots at the boss). You should lock the cursor and hide it too. I could not do a full 360 camera turn. 

Some neat ideas on display here. I enjoy having a bunch of different characters with different abilities. Feels a little similar to Gauntlet because of that!

My biggest pain points are that the controls are pretty stiff - I think that locking the cursor to the game would solve a decent amount of my issues. Because the cursor isn't locked, it was sometime not possible to turn the camera anymore, and other times my mouse would escape to my other monitor. This created some issues with platforming, and also with combat.

A lesser concern is that pressing A or D causes the character to run in an arc. This was adjustable, but not immediately intuitive!

I appreciate that there are some secrets to find, which opens itself to some replayability! The sound effects and BG music are also welcome.

Perhaps having some enemies before Teeter would be appreciated - there's a lot of large open areas before hand that feel like they're ready to be little arena fights, but I never encountered anything to fight except for Teeter!