Serious Sam the broken series made by people who lost the touch. SS4 is just broken and boring. Bigger, less detail, less functioning guns. SSTSE on the other hand is fine but playing it on hard shows they just throw enemies at you without thinking.
THEN the death traps. Too many, too badly designed. Made for multiplay, maybe. I only know that big lobbies back in the day insane, full of enemies.
Multiplayer Coop has the best integration. Hands down. OG Serious Engine. You can save and load and pull all players with you.
Back to the game. SSTFE is just fine and great. Too flat but I love it for the great maps, soundtrack and choice of guns at the right time.
SSTSE Is different. Tourist and Easy are fun, but hard throws so many enemies at you. I never noticed different spawns in this compared to 1ST-E. 1ST really differs and adds a lot of foes everywhere including tastefully placed punishments on item pickup.
2nd-E feels just stretched to be as long as possible. So many arenas with physic-games. Not enough health to save scum. Overwhelmed so that I can not even do the work between shotgun and sniper/rockets.
First maps do have height. After the first biome it is all again flat. Xmas and Medievil maps are the best hands down.
PS. The xbox Encounter Edition is uneditied. More cute looking game which has all maps intact.
HD- is different. 1ST has a endboss bug and crashes last level. HD- 2nd Encounter has 1ST-E integration and Lan Play. Fusion is a SS3 built which just ported assets to it from 1st and 2nd which changes enemy speed due to careless gready devs.
OG SS2 better than current version due to broken UZI speed and forced dual wielding game redesign and bad beta weapons being added.
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What I want to say. Multiplayer and compatibility is great. Guns are same, enemies just in punishing amounts between traps, physics arenas and more. The game is like a filler.