I purchased this game on steam when it was in Alpha 7 and I played through the entire game until I got 3 stars on every level. It takes an IMMENSE amount of strategizing. You will fail a thousand times, which makes completing the level insanely rewarding, especially with the newly implemented replay system.

A few of my friends saw me playing the game and purchased it for themselves. They had a much harder time on several levels and got absurdly frustrated at the game. This didn't stop them from playing for another 4 hours to complete that one level. I must warn you not to take this with a grain of salt. Doorkickers is extremely addicting. You will seemingly teleport into the future and wonder what happened to the last several hours.

Every update makes the game better and better. I saw some footage from Alpha 6 and the game took leaps and bounds forward in the Alpha 7 update. It's constantly evolving with new and refined features. As I write this, the game is in Alpha 8. I highly recommend this game.