Like its predecessor, Donkey Kong Jr. has interestingly varied level layouts and obstacles, but in practice I find it to be a much less enjoyable experience. Compared to Mario, DK Jr. feels worse to control, which is a kind of major problem. The single-vine vs. double-vine climbing mechanic is somewhat interesting, but not especially compelling. Donkey Kong Jr. is not necessarily a bad game, but it is nowhere near as memorable or fun as the original.

Fun & straightforward game! I really like Donkey Kong Jr's goofy expressions and the way Mario is the villain now.

Rest In Peace Donkey Kong Jr
(killed in prison by Illuminati assassin)
(knew too much about Mario's past)

I prefer the movement in this game to the original Donkey Kong, it's just a lot faster, and I think the way they expanded upon the climbing mechanics from the first was greatly appreciated. The 2nd level and 4th are probably the most intriguing in that respect, and I especially like the twist on DK's last level in this game. Sort of ironic, but I feel due to the fact it's much smoother to control, you kind of lose some of the charm and tension of the original because of that fact, and in general I just find it way easier than it's predecessor in both handling and level design.. but that's not exactly a bad thing.
It still has some of the weirdness of the first but you kind of just get used to it after dying like twice.

Great classic game. The obvious criticism would be that it's rather short with only a handful of levels before it loops but like Donkey Kong it's still rather enjoyable to pick up and play nearly 40 years later. Responsive gameplay, enjoyable levels (even if there are so few of them), and a fresh protagonist swap from its predecessor make it pretty enjoyable even if you can breeze through all the levels in a short time.

I suppose it says more about me as someone who loves old games that you can just pick up and play more than anything but I love these old Kong games, even if they aren't very long.