Crimsonland + Crimsonland Classic
Initially, I thought about posting each of the games separately, but they were similar enough that I decided to combine them into one entry. Some of the differences are the somewhat enhanced visuals, more modes (though the typing mode is missing from the 2014 version), more enemies, more weapons and the ability for 4 players to play together (as opposed to the original's 2). Other differences are noted below.
Crimsonland. Named as such, because the amount of blood spilt from the monsters you will be facing will make the ground red. In its purest form, Crimsonland is a top-down arena shooter which pits you against a lot of monsters to fight across 50/60 increasingly difficult stages (the 2014 version has 10 more stages). In almost all stages, you start with your weak handgun and killing monsters will grant you access to more powerful weaponry (as well as power-ups) that can help you clear the stage easier, or even turn the tide. The more stages you complete, the more weapons and perks are added to the game's RNG, so while you begin with some typical weapons like an assault rifle or a shotgun, you later get access to things like the ion cannon, plasma rifle, rocket minigun, etc. While not all weapons are great, those who are, have a nice weight to them and blasting enemies into little bloody chunks is always satisfying, even if the game isn't exactly a looker. The power-ups also offer a nice variety, ranging from healing and invulnerability to something like freezing all the enemies and even a small nuke in there. As for the perks, whenever you are killing monsters, you gain XP and when you gain enough of it, you level up and you are able to select a perk. The perks are numerous and randomly generated, so they might or might not offer some significant help. They can help you gain more XP, grant you some regeneration, allow you to move faster and even allow you to activate power-ups from afar.
Unfortunately, while weapons and power-ups do sport a nice variety, the same can't be said for the stages and the monsters. The stages are all flat and do not possess any interactive features at all like different elevation, structures to take cover and somesuch. It's like each stage you play was first bombarded to oblivion prior to your arrival. Actually, scratch that, there should have been craters in that case! As for the monsters, they are all a variation of one of the common enemies of the game, whether it is an alien, giant spider, beetle or zombie. Different size, colour palette-swap; that''s what you should expect for the most part.
Another thing I didn't like is the 2014 version's increased reliance on luck. In some stages, failing to get a good weapon and/or a good power-up can spell your doom, as enemies can continuously respawn through generators and failing to kill them quickly will eventually result in you getting surrounded and massacred. Also, the 2014 version's Quest mode doesn't support levels and perks, unless unlocked by a password. Even then, it's not obvious when you are about to level up as there isn't a visible XP bar (at least, I couldn't see one).
However, I must say that I appreciate that GOG includes both versions of the game, as I can play the Classic one by myself and the 2014 with my friends. Though, if you are going to play it using controllers, I recommend you find one with nice and responsive analog sticks, as the PS2 ones aren't up to snatch. Other than that, I enjoyed the game, both in single and multi-player. Full list