i have a few games i wish i could rediscover but describing them is not easy, i am unsure if these games even could be found at this point
the first one was a game where you were some sort of robot, and the objective of the game (from what i played and can remember) was to collect floppy disk shaped "data disks" and put them in various terminals around the level, i believe there were enemy robots of various types but i think i only dealth with bug type ones, as for the look of it, i believe it was a 2.5D type game.
the second one is likely a fan made game or some kind of test for a game, it was a mario (the nintendo character) themed game which was 2.5D, unlike normal mario games the player simply walked around the level and could speak to various characters (who never moved and only stood in place) after a few minutes a row of fireballs would come from the top of the screen in a horizontal line and always kill the player so i never got to figure out what it was about, i remember the level being a grassy area with shrub walls in some places and a pipe that was on the far left side of the map which was hard to reach on time and im unsure if it was useable.
the next two i played at the same time period (as i believe they were on a disk or set of disks together, possible the galaxy of games series), the first game was a really weird FPS style game where you would walk through a mostly whiteish or brick maze with a gun or fist and would kill enemies, one of the enemies was a big smiley face which made weird sounds, and you had to always watch your back as enemies would come out of nowhere and kill you.
The second game is going to be really tough to describe but here goes, from what i recal you played as a stick man or a pencil drawn guy, and you would be in a really open white or possibly textured area and would find these structures which were basically white blocks grouped together, and some of them were in geometric patters and you had to climb on and around them to find or get something, but i never got to play the game very long.
the final one is a game which i only played very briefly when i was very very young so between 95-2005 it was on a floppy disk, and all it consisted of was two 3D white octagonal polygon platforms and a rope between them all on a pure black background, you played as a bipedal reptile of some sort and to beat the first level you had to jump from your platform to the rope and land on the other platform, but i never managed as it was difficult to play and i lost the disk not long after finding it, i think the player character was green and everything else was white while the background was completely black, its entirely possible it was some sort of demo disk for something but there is no record of it at all anywhere that i can find, it would be nice to be able to at least learn the name of these extremely obscure games.