I think it would be interesting to add a new "Restricted" constructed format to go alongside Standard. Currently it's nigh impossible for new players to compete in Standard. What I envision would be limiting decks to:
1 Legend,
2 Rares,
3 Uncommon.
This would greatly encourage newer players to participate in constructed tournaments.
Impossible to go back to an earlier level? Accidentally won a level without getting perfect score, can't go back :( Can't be bothered to replay or play further.
I see suggestions for giving extra starting gold depending on how well you've done before. Please don't, nothing ruins a game more than having to grind. If you're skilled or clever enough you should be able to win on your own merits, not given free stuff.
"My first and foremost complaint is what happened to physics? When my several ton tank drops a two thousand feet onto the ground I kind of expect it to bounce"
... Then I think it's your view of physics that are flawed. Next time there's a road safety show where they drop a car from a crane to simulate a crash, go see it. Trust me, the amount of bounce is extremely limited.
Good proof of concept for game engine. Needs better levels, enemies, upgrades , difficulty etc, as have been mentioned by others. With that in mind I'd like to see a Ray Quest 2 with a lot more effort put into game design and content.
3/5
Needs disclaimer: If you want to earn cards for multiplayer, do not play campaign on kongregate. Game is decent but not worth playing the campaign twice to earn the cards. :S