Single player, by 
This is very nice. The small kangaroos are like a souped-up version of the Fencers, swapping that enemy’s defensive parries with offensive jumps that go surprisingly high and far. They’re not impossible to avoid, but will certainly present a greater challenge than most vanilla enemies, which is a point in their favour as far as I’m concerned. One complaint I do have is that whereas all original enemies have a simple looping idle animation, these kangaroos stand completely still while not attacking. Which is fair enough, as animations are a lot of work, but it does look a bit strange and makes it obvious that these are imported rather than vanilla enemies.
The boss is a bigger and badder version of the small kangaroos, adding extensible boxing gloves to simply jumping at you to attack. The boxing gloves are a nice idea but perhaps a little too hard to avoid, reaching high enough that they’re very hard to not touch even when double-jumping over the kangaroo. This would perhaps be worth balancing a bit more.
But overall this is a very useful addition to the game, giving single player level makers more tools to work with and adding some variety to JJ2’s by now stale palette of enemies.
