Okay, I just played three games through (dying twice).
Like Envirobear, this game obviously has to be taken with a grain of salt and a sense of humor. You control a conestoga wagon as it travels to find the city of El Dorado. Gameplay consists of navigating triangular hills with your wagon, adjusting midair in jumps to land properly, some decision making, and hunting animals.
The main gameplay is navigating the hills. Hills are triangular and so you are constantly jumping off and flying. You have to adjust your wagon's angle as you jump off of hills in order to not land upside down (and take damage) or get stuck. You can make multiple loops in mid air at times.

This is the most fun and frustrating part of the game.
Along your way, you encounter villages, where you can decide between two random decisions-- among those being rest, see a doctor, trade for food, trade for ammunition, and others. There are Indian tribes which will give you a random good or bad effect. If you stay too long in a river people will get sick. There are also snakes, bandits, and other events. There are more options than the original PC version because of this, and sometimes you may have to make difficult decisions.
Hunting is pretty silly. You shoot from your wagon at animals, and then you have to pick up the meat they leave when they die. Sometimes when you hit an animal they go flying across the screen, or the meat they leave gets stuck in a hill (pretty certain this is a feature and not a bug). There are also food-stealing bandits you can fend off with your gun. You have a limited amount of ammo.
The food system steadily decreases and can only be increased by hunting or trading at places. If you run out of food, you lose. If everyone dies to disease/damage/other things, you lose. You win by finding EL Dorado.
I would say that this game has a lot of charm, but it isn't as ridiculously silly as Envirobear. Sometimes it feels like you get stuck in the semantics of just going up the hill at the correct angle, backtracking to get a jump, etc. instead of constantly moving along. The food is a little too generous and you rarely run out, The controls aren't bad but they are of course designed to be crazy. There are awesome moments when you succeed and make a perfect dismount with your wagon.
I'd say buy if you want something silly and fun, but not if you want something serious.
Oh yeah- it's definitely harder than the original PC version.