My boyfriend and I toured Europe in the summer of 2006 using rail passes. During this eventful and very enjoyable six weeks we stayed in many hotels - some were good, some were bad, some were average, but there were none quite so dire as the Mercure Mulhouse. From the start, the day we stayed there did not go well; having booked the hotel on a website in the morning, we hopped on the train from Paris to Basle, taking about 9 hours. When we arrived in Basle at 11pm (having not eaten for the best part of a day), we proceeded to the Mercure in Basle (as the website had directed us) only to find that we were actually booked into the Mercure in Mulhouse. The Mercure in Basle had plenty of free rooms, but as we had already paid for the Mulhouse hotel, they would not transfer our booking. We were, however, given vouchers for the taxi ride back to Basle train station. So, at about 11.30 at night, we dragged our weary selves on the train and back over the border to France.
Once we arrived in Mulhouse, we proceeded straight to the hotel, mercifully right next to the train station. Once we got there, we were informed that, despite our having booked a smoking room, we were in non-smoking, and the (extremely rude and unco-operative) receptionist informed us in peremptory tones that it would not be changed. This would not normally matter, neither of us being heavy smokers (I have quit since then); however, after the day we had just had, being denied a cigarette felt like the final nail in the coffin.
Alas, it was not so.
Once we got up to the room, we noticed that in the bathroom, the bath was full or hair, the wastebin was full of rubbish, and the toilet bowl was full of something that belonged to neither of us. When we called reception to ask them to clean it, it was done after a certain amount of negotiation and with extremely bad grace. We went back downstairs immediately to find some food, and were informed by the receptionist that there was nothing that the hotel could provide us with, and nowhere we could get food in the area surrounding the hotel, despite our pleading that we had not (by this point) eaten in 16 hours. We left the hotel and wandered about for 90 minutes, at the end of which we found a place where we got a small plate of chips and a can of juice each for about 10 euros. As we were a captive audience by this point, we paid it. Once we got back to the hotel, we found in a street directly behind it (in the opposite direction to the one in which we had walked) several food outlets, open and busy, which the receptionist had not seen fit to inform us of.
Thinking that our troubles were over, we went back up to our room. Sitting down on the bed, we discovered several used hankies in between the bedcovers and sheets. Evidently, the entire room had not been cleaned, and not just the bathroom. When we phoned reception, they were even less helpful than before, objecting as we had not told them of this on the previous call about the bathroom. When someone came up to clean it, we again received no apologies. We passed the night there and left in the morning, vowing never to speak of that day again - except to warn other hapless travellers so that they might avoid a similar fate.

The centre of Mulhouse is currently full of roadworks and the hotel was a little more difficult to find than it should have been. Once we found the hotel the secure parking was fairly easy to access.
We stayed in the hotel on one night of a tour of the region and a little more research would have paid dividends, Mulhouse is a sprawling industrial town that makes very little of it's old town. A few miles further would have taken us to Colmar which is a much more attractive proposition
The Mulhouse Mercure is an average chain hotel with acceptable rooms. The buffet breakfast was however a disappointment - probably the worst on our tour.
If you are staying on business (Peugeot HQ is close) then the location is OK. If you are touring then I would recommend taking the time to go the few extra miles to Colmar