Really great game. Nice art, satisfying gameplay. Controls are just barely simple enough for it to be playable on my Flatbox. No analog sticks or mouse needed. Lots of fun with friends. It's got some rough edges and bugs that will probably never be fixed due to there being 1.5 sequels out now, but still worth playing. Controller support has a lot of issues and you will probably have to reset your controls every 3 sessions or so. Survival mode has some balance issues like Paladin's shield not blocking magic projectiles, making the later parts extremely difficult. I hear in later games they made the shields block magic. Some menus can't be fully navigated with a controller, which would probably be easy to fix if they wanted to. The secrets in the campaign approach unreasonable territory. I think they're trying to emulate very old games and get replay value via artificial difficulty. If you want all the achievements you're pretty much going to have to use a guide. One achievement requires you to screw up in a very particular way during a campaign run which is annoying. Between the separate achievements for beating bosses on Medium and Hard, all the secrets, and the requirement for at least one semi-failed run, you'll probably have to run through the main campaign several times to get every achievement.
If this game were free software I think the community could polish it up nicely. The core of it really is good, but the more I play it lately, the more the little issues start to bug me.