[quote name='Duminakan89']It's pretty damn fun, especially with another player; has anyone played the previous one? If so what differences are there between 1 & 2?[/QUOTE]
Sequel has more types of enemies, new traps, co-op. The biggest difference is the upgrade system. In the last game, you spent skulls to upgrade an item, but it was just one upgrade and they were permanent. In this, there are multiple types of upgrades. There are 3 of tiers 1 type (often damage) and then 2 unique types you can choose (like a trap have a further reach or slow effect). You can refund all your skulls as many times as you want, so you're encouraged to experiment.