Corkscrew

The main thing is obviously a good game. I've played Ocarina of Time multiple times simply because it's so good. Open-world/Sandbox style games are generally good to replay because they're different every time. You'll never play the same Minecraft, SimCity or Elder Scrolls game twice. As has been said, unlockables are good in multiple ways. Super Smash Brothers Brawl encouraged players to complete the All-Star Mode with every character for a reward (Music, Stages, Stickers or just simply another trophy); this is good for completionists. Portal unlocked harder versions of already complete levels as well as dev commentary and challenges. This works in two ways: It makes people play the harder levels and they'll go back and play the original level to complete it with as few portals as possible or in the fastest time. Portal also offered a variety of different solutions to the one problem so players can try to find the best one. The Lego games encouraged replaying and unlocking new characters by locking off certain areas in levels in the Story Mode. This means you'd have to go back in Free Play with a character the player's unlocked to access that area. Multiplayer adds a huge element as players need the best upgrades and unlockables to compete. Putting these unlockables into the story mode supports replay. DLC also keeps in players since their's streams of new content.

Summing up: Content is probably the most important things. If the player can get new content or experience the game differently then they'll probably keep playing.

b]What: [/b] Multi-stage Enemy (like Tozegos from Zelda)
HP: 3/10
Strength: 5/10
Weakness: Underground Attacks
Extra: You'd have to flip them revealing their sensitive underside, then attack again to kill them

I agree with the prevailing opinion. Magecraft doesn't really have a connection to Minecraft but some players may think that at first. If it's something that you believe is a concern then just find another title. Most RPGs can be called anything from the game (Characters, Locations, Items, Story Points) so you shouldn't have much difficulty. Something that sums up the game quickly is usually the best.

Lots of people enjoy hardcore platforming. If the game is well made people will probably enjoy it no matter how hard it is (not always true, though). If you have everything you plan to have then it seems to be a great game. A little story can sometimes help keep things together. Even a small one indicating why you are finishing each level (Like 'They Need to be Fed') rather than random jumping and shooting.

Sorry. Double Posted for whatever reason.