Designing Hot Potato: Thy Spud Consumed (DOOM SnapMap)

One of the main reasons I decided to get DOOM on release was the SnapMap tool. I enjoy level creation tools and I missed out on the Mario Maker craze, so this was gonna be my Mario Maker (with guns). One of the maps I created got a bit of traction and was featured on sites like RockPaperShotgun, YouTube channels like GamesRadar+, the actual game’s Community Picks and even Bethesda’s SnapMap stream. The feedback has been overwhelming, so I wanted to talk a bit about the thought process and design of the map itself.

After playing a good chunk of the DOOM campaign and not really enjoying the multiplayer, I went ahead and streamed SnapMaps a bit. I played other maps while waiting for inspiration on what to make. Considering this was release week, the maps only touched upon the surface of what the tools could do. One map, which I don’t remember the name of, just had very long hallways with a ledge you could double jump to. While the map wasn’t really exciting, it reminded me how fun moving around in DOOM actually was. This was the basis for “Hot Potato”, a map I wanted to make during that same stream.

The pre-made room modules SnapMap uses had some choices that caught my eye. Namely, a module with at least two exits often had vastly different ways to get from one door to the other. There was an obvious path and a dirty shortcut in almost every instance. The fact that a double jump can be executed at any point of a jump or fall also meant plenty of air control. With all this in mind, I assumed that a parkour-styled mode would be fun. Now, there were some parkour maps that shipped with SnapMap, but I personally did not like them. They focused on precision-based parkour which is not something I think DOOM’s movement is good for. So I decided to go for “optimized route” parkour, focusing more on timing and figuring out a route, rather than actually trying to hit a platform.

Adding a sense of urgency was also important. Why would the player be in a rush? A time limit felt a bit passive to me, so instead I opted in for a gradual health decrease (explained in-game as carrying a radioactive core, hence “hot potato”). That also meant I could guide the player with health drops and use it to optimize the map’s difficulty. And so, the first Hot Potato (which I now consider a prototype) was born.

Looking back at it now, there are a lot of things I’d change, but for a first map attempt, I thought it was good. I later spent some time making a multiplayer mode, but since I needed to do playtesting for it and it was a bit hard to organize a 4-person group, I decided to do another single-player map. Since I had familiarized myself with the tools far better, I wanted to expand on Hot Potato and make it bigger and meaner. Thus began work on “Hot Potato: Thy Spud Consumed”.

My main design goal for this iteration was to always give players interesting choices. However, when you are under time pressure in a level, it is easy to not even notice a shortcut or alternate path. Another major problem was that certain modules were massive or confusing; they had an interesting layout that I wanted to use, but players unfamiliar with them would need to search for exits. To solve this, I went with the tried and true platformer method of using “coins” to guide the player. This also meant I could better balance the health gain vs damage in a section. Whereas the players relied on rare big heals in the prototype, here it would be frequent smaller heals.


I thought about what the “coins” (they’re more like containers, but lets call them coins) could also do. I decided to have them actually give the player a currency they would use in a shop. An official horde mode SnapMap I played had a shop, hence the idea, but I didn’t like the way it was laid out, so I wanted to try and make it more classy and snazzy. I think shops without a good shopkeeper are generally a waste, because it’s always a good opportunity to have a character that makes you feel welcomed or entertained. Think about Resident Evil 4, Wonder Boy the Dragon’s Trap, or Killing Floor? However, given DOOM’s aesthetics, the closest I could come to a likable person was the Cacodemon, so that’s what I went with. He’s surprisingly nice when he’s not trying to murder you! This is also why I added the ability to talk to the Cacodemon. I added a few random lines and he picks one whenever you talk to him. Apparently, the phrase “YOU LOOK LOVELY TODAY, MORTAL” was the most popular one (it’s my favorite, too).

Shops that sell upgrades are generally scaled with a rising challenge, however, Hot Potato’s works differently. The shop’s primary function is to make the game easier for players that are struggling. The map was tested and is beatable with one try and one shop visit per checkpoint, but it requires memorizing the map and having flawless execution. Since you keep your coins when you die and since coins respawn after 10 seconds, it means that the more you die, the more coins you have. This means you will be able to buy more expensive upgrades and make a section easier for you. However, since coins don’t give you points, players who die less will have a higher score. The upgrades the player can buy are broken down into health, speed and radiation resistance. The first two go up to rank 10 (health caps at 200 and speed at 300%), while the more expensive radiation resistance goes to rank 5. Rad resistance affects how much each tick of radiation damages you, and it goes from 10 to 5 damage at max rank. Initially, it worked like the other two stats, but it was too powerful during testing. This second variant ended up being a nice middle-ground.

In addition to the coins, the player can pick-up “donuts”. They are unique pick-ups that don’t respawn, don’t give you health, but give you more coins and points. To be honest, I just saw that there was a rotating donut model and I really wanted to use it. However, this ended up helping with the more “interesting choices” approach of the map design. Namely, each donut gives the player 70 points. This might not seem like much, but it’s the equivalent of 7 seconds on your time bonus. Each donut is placed so that you need to risk time and health to get it, but if you pull it off properly, it never actually takes more than 7 seconds. While the player isn’t meant to collect every donut, getting the best score on the leaderboard requires planning which donuts you’ll pick-up.

I should probably cover scoring now in more detail. There are three factors that determine score: completion, time, donuts. Completion is a fixed score you get for reaching the end of each section. The later the section, the more points (1000, 2000, 3000 respectively). This was in order to avoid the hypothetical scenario of players finishing a section with no time or donut bonus and having nothing to show for it. The time bonus starts at 3000 and is decreased by 10 every second, meaning if a player takes more than 5 minutes to complete a section, they get no bonus. The timer starts the moment the player picks up a core for the first time and ends when it is put in its slot. That means that between sections, players can take all the time they need to shop and rest, but once they initiate a section, they need to be quick about any upgrades. Finally, as mentioned before, each donut gives the player 70 points at the end of the completed section. This kind of scoring system was more versatile than relying on SnapMap’s built-in Par Time. It also means that a second of difference is clearly displayed on the leaderboards.

The actual level introduces new elements with each section, to give them a unique flavor. The first section is just vanilla running through various rooms. The second introduces lasers that shave off your health when in contact with them. The final section combines the lasers with plasma hazards on the floor which do massive damage. The lasers aren’t always meant to be avoided. While finding a route without lasers is quite possible, some of the best routes involve taking damage to save time. The plasma floors don’t adhere to this though and they are meant to always be avoided.

There are a few things I wish I could change about the map or that I wish SnapMap had let me done. One bug stopped me from spawning lasers after a certain point, so I had to be more stingy with my placement than I had wanted to be. The object/network limit stopped me from adding another section (the actual map grid had space for one more). I also wanted to include a give-up panel that let players quit the map in defeat. This would have let me keep track of the leaderboards to see how far players had gotten. I also wish I had added a few more Cacodemon lines and adjusted some checkpoint teleporters a tad (speficifally Checkpoint #1’s destination is on a confusing angle). However, despite being possible to do those changes right now, they are just tweaks, and SnapMap resets leaderboards apparently when you update the map, so I don’t think it’s worth it because the map is score-oriented.

One mistake I almost made was lock the shop behind the first checkpoint. Literally a few hours before people picked up on the map, I decided to make the shop accessible right away (I realized the first section was actually very difficult and the shop was meant to help with that). This ended up being a very good decision, since the Cacodemon became the face of the map and is what made people want to try the map in the first place.

All in all, I enjoyed working on the map and I enjoy SnapMap despite its limitations (I’m one of those people who prefer silly limitations). If you want to try out another map I made, here is a video on VIPER Sniper. It is a 3v1 multiplayer mode where one powerful sniper has to control points while security tries to kill them. It’s like Scotland Yard (the boardgame) with guns. Sadly, it’s hard to get exposure for multiplayer-only SnapMaps, let alone 4-player ones, but I enjoyed developing it and playing it with friends.

If you own DOOM, you can find Hot Potato: Thy Spud Consumed by searching either for #hotpotato or ZGLRZC92 in the game.