I was a bit on the fence when I saw semi-cooperative, but you have options for that. You can play the game in campaign mode or one-off mode, and from there you have the option of full competitive, semi-cooperative, or full co-operative.
I've only played Green Hill Zone so far, which hasn't been difficult, but I'd expect the later zones and the unlockables to be much tougher. Basically, you have 3 options for building a dice pool each turn, and then a few things at your disposal to mitigate bad rolls.
Without spoiling too much, this game can technically go up to 6 players, which I tried once. Played fine as it was, but made the robotniks a bit too easy, so I'll probably come up with a house rule to balance that one out.
